The Obesity Code aims to clear up myths on weight loss, and provide a simple formula for long term success. Below I’ll discuss aspects from the book, including an example diet plan at the bottom.
Since writing The Obesity Code Jason has followed up with The Diabetes Code (aimed at helping people prevent or reverse type 2 diabetes), and The Complete Guide to Fasting (which covers intermittent and extended fast details).
Jason Fung – Author of The Obesity Code
Hormonal Roots of Obesity
Jason suggests that to understand weight loss requires understanding the hormonal roots of obesity. He explains that the hormone insulin is the key driver of obesity. Therefore obesity is a hormonal, not a caloric imbalance. He recommends we focus on two key areas:
- What to eat
- When to eat
What to Eat & What Not to Eat
What to Eat?
The book doesn’t tell you specifically each and every food you should eat. Instead Jason outlines some general principles for eating:
- Reduce intake of refined grains and sugars
- Moderate protein consumption
- Increase natural fats
- Maximize protective factors such as fiber and vinegar
- Choose only natural, unprocessed foods.
What Not to Eat?
Jason mentions a few specific examples of what not to eat:
- Sugar – Don’t add it to anything you eat or drink. Check food & drink labels to ensure sugar hasn’t been added to anything you buy. See below for other common names of sugar*.
- Snacks – Jason recommends you cut out all snacks between meals. Constant stimulation of insulin leads to insulin insensitivity.
- Sauces – Barbecue, plum, honey garlic, hoisin, sweet & sour and other dipping sauces contain large amounts of sugar. As do commercial salad dressings and ketchup.
- Candy – It probably goes without saying that chocolate and sweets should be avoided completely (except for dark chocolate that’s 70% cacao content or greater).
- Desserts – these are generally high in sugar and should be avoided. Replace with seasonal fruits (optionally with whipped cream) or dark chocolate. Save less healthy desserts for special occasions, but don’t make them a regular occurrence.
*Other common names for sugar are sucrose, glucose, fructose, maltose, dextrose, molasses, hydrolyzed starch, honey, inverted sugar, cane sugar, glucose-fructose, high fructose corn syrup, brown sugar, corn sweetener, rice/corn/cane/maple/malt/golden/palm syrup and agave nectar. Don’t let manufacturers trick you into consuming excess sugar under the guise of a different name.
Then in regards to the highly glycemic, popular staples; bread, pasta, potatoes and cereals…
Bread & Pasta – Jason suggests the consumption of bread and pasta should be minimized for a number of reasons:
- Low nutritional value (processing removes most fibre and vitamins)
- High glycemic effect (big increase in blood glucose level, which then requires a spike in insulin to regulate it)
- Easy to over consume & may be addictive
Rice – Jason notes that many Asian populations have eaten diets based on highly refined white, polished, rice. Yet, until recently, obesity and diabetes remained rare in these populations. It has only been since they added sugars and processed foods to their diet, that obesity and diabetes have become rampant. This shows us that it’s possible to consume white rice and stay healthy. However, for those looking to lose weight, white rice is highly glycemic, and should be minimized.
Potatoes – Jason notes that potatoes are highly glycemic and consumption should be minimized. He does however point out that potatoes served cold and dressed with vinegar as a salad had 43% lower glycemic index1 – in part due to the cold increasing the resistant starch content of the potatoes.
Cereals – Jason has two main messages for breakfast. The first is that it shouldn’t be considered “the most important meal of the day”. If you’re hungry in the morning, and want to eat; do. But if you’re not, and instead want to break your fast at midday with grilled salmon and a side salad, then that’s perfectly acceptable. Jason’s second message is that many breakfast foods such as cereals, breads, muffins, Danish pastries etc. are highly problematic, and should be avoided. If you must eat cereals, he says, eat those containing less than 0.8 of a teaspoon (4 grams) of sugar per serving.
Foods Jason Specifically Recommends:
- Eggs – Inaccurately demonized due to cholesterol concerns, eggs are in fact incredibly healthy. They can be enjoyed in many ways, including scrambled, over easy, sunny side up, hard-boiled, soft-boiled, poached, etc.
- Seasonal fruits in moderation
- Traditional yogurt and Greek yogurt. Make sure they are sugar-free.
- Oatmeal – whole and steel-cut are good. Avoid instant oats which often add sugar.
- Nuts – Macadamia, cashews, walnuts and pistachios are all high in healthy monounsaturated fats and low in carbohydrates. Watch out for peanuts, which aren’t technically a nut (they are legumes) and should be consumed in moderation.
- Coffee & Tea. Avoid adding sugar or sweeteners. Cinnamon or other natural spices can be used to enhance the flavor.
- Wine – moderate consumption of red wine (up to 2 glasses per day) typically does not impair insulin sensitivity, and therefore may be enjoyed.
- Bone broth. See below for more details on bone broths.
(Note: this list of foods Jason recommends in Obesity Code is not exhaustive, for example it doesn’t mention things like meat and fish, which Jason is a proponent of. You can reasonably assume that if food is natural, unprocessed and consumed in moderation; it’s ok for Jason’s diet protocol).
The hormonal obesity cycle – showing the effects of excess glucose and fructose (image via IDM program)
When to Eat
- Balance insulin-dominant periods with insulin-deficient periods (balancing feeding & fasting). Eating continuously is a recipe for weight gain
- Intermittent fasting is a very effective way to deal with when to eat
Sleep
Beyond what to eat & when to eat, Jason touches on another factor that affects insulin levels; sleep. Not only does sleep affect insulin sensitivity, it also affects our ability to self-control, and our desire for carbohydrates (increased grehlin levels, which is a hormone responsible for hunger signalling). Thus people who are chronically sleep deprived will often (through no fault of their own), make more impulsive food decisions, and crave more carbohydrates. Therefore its important that if sleep deprivation is a factor, it gets tackled alongside the dietary choices.
This image shows the difference in insulin secretion between a diet with no snacking, and a diet where food is constantly consumed. Insulin = energy storage. Therefore you want to have decent breaks in insulin secretion for a healthy body.
Sample 7-Day Meal Plan – 24-hour Fasting Protocol
The below meal plan effectively means that every other day you are partially fasting from dinner through to dinner (24 hours). To make this slightly more do-able, Jason suggests incorporating a cup of vegetable, chicken or beef broth in place of where lunch would be.
Treat the exact contents of the meals as guidelines only, to be tweaked to your own taste. If you need to increase the quantities of food to reach satiety, do so. As long as when you’re fasting, you stick to it.
You may notice that only 3 of the 7 days include a dessert for dinner – this seems to be Jason’s way of explaining that sweet foods should be an occasional treat, rather than consumed daily.
| Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday | |
| Breakfast | FAST DAY Water Coffee |
Western omelet Green apple |
FAST DAY Water Coffee |
All-Bran Buds with milk Mixed berries |
FAST DAY Water Coffee |
Two eggs Breakfast sausage/bacon Strawberries |
FAST DAY Water Coffee |
| Lunch | FAST DAY Water Green tea 1 cup of vegetable broth |
Arugula salad with walnuts, slices of pear, goat cheese | FAST DAY Water Green tea 1 cup of chicken broth |
Ginger chicken lettuce cups Stir-fried vegetables |
FAST DAY Water Green tea 1 cup of beef broth |
Baby spinach and lentil salad | FAST DAY Water Green tea 1 cup of vegetable broth |
| Dinner | Herbed chicken Green beans Mixed berries for dessert |
Asian grilled pork belly Baby bok choy stir-fry No dessert |
Halibut pan-fried in butter and coconut oil No dessert |
Indian chicken curry Cauliflower Green salad No dessert |
Baked catfish Sautéed broccoli with garlic and olive oil Seasonal fruits for dessert |
Peppered steak Asparagus |
Grilled chicken salad Dark chocolate for dessert |
Note: On mobile devices, you may need to scroll right to read the full table.
In case it’s of use, I’ve made a PDF version of the above table so you can print it out. Additionally I’ve made a second version with empty spaces for the meals, that way you can program your own meal details:
- PDF printable version of above table – 24-hour fasting protocol
- PDF printable version of table with fast periods + the rest blank – allowing you to input your own meal programming
Sample 7-Day Meal Plan – 36-hour Fasting Protocol
This version differs from the above, in that rather than fasting from dinner through to dinner every other day, you fast from dinner through a whole day, until breakfast 2 days later (again, repeating the fast every other day).
| Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday | |
| Breakfast | FAST DAY Water Coffee |
Western omelet Green apple |
FAST DAY Water Coffee |
All-Bran Buds with milk Mixed berries |
FAST DAY Water Coffee |
Two eggs Breakfast sausage/bacon Strawberries |
FAST DAY Water Coffee |
| Lunch | FAST DAY Water Green tea 1 cup of vegetable broth |
Arugula salad with walnuts, slices of pear, goat cheese | FAST DAY Water Green tea 1 cup of chicken broth |
Ginger chicken lettuce cups Stir-fried vegetables |
FAST DAY Water 1 cup of beef broth |
Baby spinach and lentil salad | FAST DAY Water 1 cup of vegetable broth |
| Dinner | FAST DAY Water Green Tea No dessert |
Asian grilled pork belly Baby bok choy stir-fry No dessert |
FAST DAY Water Green Tea No dessert |
Indian chicken curry Cauliflower Green salad No dessert |
FAST DAY Water Green tea Seasonal fruits |
Peppered steak Asparagus No dessert |
FAST DAY Water Green tea No dessert |
Note: On mobile devices, you may need to scroll right to read the full table.
- PDF printable version of above table – 36-hour fasting protocol
- PDF printable version of table with fast periods + the rest blank – allowing you to input your own meal programming
Bone Broth
A core aspect of Jason’s diet regimen is the consumption of bone broth on days when fasting. There are a few key benefits to this:
- Its low in calories and almost zero carbohydrates, thus not impacting significantly on the health benefits of abstaining from food
- Its high in amino acids such as proline, arginine and glycine, as well as minerals such as calcium, magnesium and phosphorus
- The salt and minerals help with staying adequately hydrated during the fast
Vegetarians – The substitute to a bone broth would be a vegetable broth. So you’d essentially just cook a vegetable soup (without blending), then strain the vegetables and leave the low carb, tasty wholesome broth.
Simple Bone Broth Recipe
At its core bone broth is very easy to make, it’s essentially the simmering of bones for 12+ hours. If any complexity creeps in, its in the sourcing of good bones, and then the additional ingredients that add to the flavour. These are the key things you need to begin:
- Having a slow cooker (aka crock-pot) is ideal – but if you’re cooking on the stove, you just need to make sure you have a large pot
- Sieve or strainer at the end to separate bones from the broth
- Chicken or beef bones
- 1 tablespoon of vinegar to help extract the bones nutrients (Apple cider vinegar is a healthy choice)
- Sea salt (or pink Himalayan salt) to taste
- (optional) Additional seasoning and vegetables, to taste
If you’re cooking a chicken broth, perhaps the simplest way to acquire the bones is to purchase an (ideally organic) chicken. Cook it and first use it for the meat, then when finished, use it for your broth.
When you’re packing the chicken into your pot, its beneficial to crack some of the bones to let out more flavour and nutrients. This can be done by pushing down on the carcass until you hear cracks, alternatively some people go as far as to individually crack the bones with some scissors.
For a beef broth, it’s generally easy enough to source bones from a local butcher or market. Ideally grass fed cow bones, although this pushes the price up. That said, one of the core benefits of grass fed beef is the quality of fat (e.g. omega3 to omega-6 ratio) obtained, which doesn’t apply to bones so much.
N.B. Having a little meat left on the bones is a non-issue, given that you’ll be straining the contents at the end.
Bone Broth Cooking Steps
- Place bones in a pot
- Add a tablespoon of vinegar (to help bring out the nutrients)
- Season with salt, and optional extras like pepper or herbs
- Cover with water
- Bring to the boil, then reduce heat until simmering
- Initially there may be some fat build up on the surface, which can be skimmed off
- For chicken bones, cooking overnight is often enough time, up to 24h is not uncommon
- For beef bones, overnight is possible, but due to being stronger than chicken bones, beef often needs a bit longer (say 24 hours)
- When finished, strain the broth into containers
- Let cool and then refrigerate or freeze what you don’t plan to immediately consume
See YouTube for a good beef broth example video and a good chicken broth example video.
Shop Bought Bone Broth
Whilst shop bought bone broths generally aren’t as good, or nutritious as a home made broth, they’re a good option when time is limited. Especially when the core focus here is to adhere to the fasting protocol itself. The bone broths are just a component of the overall plan.
Two off the shelf broths with good reviews are Pacific Organic Chicken Broth & Kettle & Fire Beef Broth. Pacific’s version is more affordable, but has a bit less marketing hype behind it.
The above is just a tiny snapshot of Jason’s book. The full thing contains vastly more content, including discussion of:
- Disease prevention
- Tips for fasting and intermittent fasting
- + more!
You can find the full version of The Obesity Code on Amazon.com, along with Jason’s other bestsellers’ The Diabetes Code and The Complete Guide to Fasting.
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Hi Alex,
I just ordered the book. I’m so intrigued by the comments and reviews thus far and I’m confident I’ll be able to handle the meal plan thanks to your summary. However, there’s no mention of alcohol. I read that 2 glasses of wine are acceptable. But what if you have an off day and end up at a party. Are there any recommendations you can offer?
Thanks agai
Hi Pam, as you mention, Jason doesn’t put up any brick walls against the casual couple glasses of wine, assuming you don’t go overboard. What I would say though is to abstain from the alcohol when you’re fasting, saving it for when you finish.
Hi, I just finished Fungs’ The Obesity Code, having read Taubes’ Why We Get Fat just prior.
Q: Fung mentions a target of 20-30% of daily calories for protein, but I do not see a target amount for the two other macro-nutrients – fat and carbs (veggies) – is there a target range and can you provide it? Thanks,
Bob
Hi Bob, thanks for your message. I concur with your post, I haven’t seen Jason specify a macronutrient target for carbohydrates and fat.
Btw, I read Taubes’ Why We Get Fat & Good Calories, Bad Calories also. Incredibly well researched and written, big fan of Gary’s work.
I have recently had a friend who’s husband lowered his cholesterol by 100 points. I have three stents in my heart and am on medications. Will this diet help me? I am 50 years old 6″2 and rather thin already.
Hi Christina. With regards to your particular situation, which is advanced atherosclerosis, I would probably suggest you focus on tackling that specifically. Whilst Jason’s main prescription (fasting) is unlikely to worsen atherosclerosis on its own, you’re already thin as you say, so it’s equally important to get your regular day to day diet (and supplements) dialled in.
Unfortunately atherosclerosis is relatively complex, and it’s not helped by the mainstream oversimplification of good and bad cholesterol. Where in fact, we want to be looking at a whole host of markers, including lipoprotein particle size, triglycerides, c-reactive protein (inflammation marker), Lipoprotein(a), homocysteine, and more.
I’m not sure if you’re familiar with Genova Diagnostics? They do a number of comprehensive blood tests in this regard, including one called CV health, that looks specifically at cardiovascular risk markers. The next step is interpreting the results and then learning about what you can do to improve them. For example, if you know your homocysteine level is high, there are specific steps you can take to mitigate that (such as supplementing specific methylated B-vitamins). Or if you have high Lp(a), there are experiments using supplements like Niacin to get it down. The latter – Liprotein(a) – may be particularly worth checking, given the early onset in your situation. See this YouTube videofor more context on why it may be worth checking.
But essentially none of that should be guessed at. You first want to know your personal results, and then take action on them.
Someone who knows a lot on this subject is Dr Joel Kahn, and there’s a relatively good amount of YouTube content of his available online. Also, Peter Attia has a lengthy post on the complexities of cholesterol, called “The straight dope on cholesterol“, which may also be interesting (granted it takes some effort to work through).
Hopefully there’s a couple suggestions there that push you in a positive direction.
Christina, please get a copy of Dr. Caldwell Esselstyn’s “Prevent and Reverse Heart Disease”. The only diet that has proven to reverse atherosclerosis, published in the medical literature, with CT scans confirming, is detailed within. It is NOT expensive, does NOT require supplements and tests. It’s the diet that saved Bill Clinton.
Thank you for the contribution Karl. Both the book “Prevent and Reverse Heart Disease”, and the accompanying cookbook “Prevent and Reverse Heart Disease Cookbook: Over 125 Delicious, Life-Changing, Plant-Based Recipes” look interesting. I will have a read myself.
One stipulation I would add is that whilst you say following this diet “does not require supplements and tests”, I think it’s rational to use tests (where possible) when making any big dietary modification, especially when you have a clearly defined outcome in mind. Otherwise you’re taking a shot in the dark. Everyone’s DNA and epigentic profile are different, and what’s optimal for one, may not be optimal for another. Without feedback (tests) it may be impossible to gauge if you’re achieving the desired results.
I’ve been reading the book and it sounds interesting. The question I have is does this help much with very obese people? Say like six-foot-two and 550 lb. because I’m wanting to avoid the bariatric surgery but I’m not sure that I’m not too far gone.
Hey Jim. The crux of Jason’s obesity code book is around fasting. Whilst he does advocate a healthy diet (as you can see from above), the majority of the weight loss is achieved during the fasting periods.
It would make sense to give fasting a go, with or without the bariatric surgery. I personally found fasting to give me a new relationship with food. Along the lines of “oh shit, I don’t need to eat multiple times per day just to stay alive’. That alone is worth it for the perspective change. Let me know if you have other questions.
I am in the process of reading the book and find it to be very interesting. My husband is a diabetic and in very good shape but cannot seem to get his sugar down and I have been struggling with the same 10 – 15 lbs for the last 30 years. Would like this to stop. We started with 24 fast right away and was wondering if it is OK to this for 4 days in a row and then 3 days off.
Hi Francesca, with regards to your plan to do extended fasts, it’s certainly possible. The main thing (especially when diabetes is involved), is to ensure you’re not taking any medications, or have any underlying medical conditions that could be affected by the fasts. Your doctor will be the best person to consult on this. I recently came across the fasting subreddit, where there are lots of people doing extended fasts, it may be interesting for you to check out.
There is something that bothers me about recommendations, here and elsewhere, to avoid wheat. No one seems to talk about the difference between Heritage wheat, which I use, and the GMO dwarf (Green Revolution) wheat. The explosion in obesity worldwide seems to correlate with the change worldwide to the use of this modified wheat, about 1981. It seems a terrible thing to happen to the Staff of Life. I do not feel well eating GMO wheat, but have no problems with the original.
Hi Aileen, it’s an interesting point, and something Jason does touch on in the book (dwarf wheat vs older wheat strains). He quotes a figure saying 99% of all wheat grown is either dwarf or semi-dwarf varieties – which is quite extreme. I’d imagine most people don’t realize there are even different strains of wheat available (I didn’t), they just think wheat is all the same. When you eat your Heritage wheat, do you buy the flour and then bake the bread yourself?
In terms of wheat and obesity, I would push back on the notion that it’s primarily to do with modified dwarf wheat. We also need to factor in the vast increase in sugar and processed food consumption too.
Thanks for this summary. I’m currently on Day 6 and down a few pounds. My cravings for sweets is almost gone. Can you eat any rice or potatoes or breakfast cereals?
Hi Carol, thanks for the message, and good questions. I’ve actually updated the post as a result to touch on what Jason says about rice, potatoes & breakfast cereals. Check under the section “What not to eat”, and let me know if you have any questions.
In a nutshell, I’d definitely try to avoid breakfast cereals. Jason says that if you must eat breakfast cereals, aim for those with less than 0.8 of a teaspoon (4 grams) of sugar per serving. And then for your continued weight loss, minimize consumption of rice and potatoes. These both have a high glycemic index.
Hi
I’m at the end of my second week of this plan, and am finding it so much easier than I thought I would. I actually quite enjoy the fasting, I have increased energy and am totally satisfied when I do eat. The cutting out of sugar and snacking is something I never thought I would manage, but it’s been so simple.
One question. We are encouraged to eat natural Greek yoghurt, and I’ve been enjoying it with homemade muesli and a handful of berries for my breakfast. I noticed on the yoghurt carton that it contains sugar however. I’ve looked into finding one with no sugar but I read that a natural sugar is produced on the production of Greek yoghurt, so there will always be some in there. Is that true? Should I restrict how much I eat? Thanks 😊
Hi Lynne, great to hear the fasting is working out. With regards to yogurt (greek or plain style), they are made from milk, which has a form of sugar (galactose + glucose) called lactose. And thus because it’s in milk, it’s in yogurt. It’s a relatvely low % of the overall yogurt (~10% or less), so shouldn’t be a huge issue, if you’re just having a few spoons each day. Just make sure there’s no additional sugar on the ingredients list.
Hi. He mentioned about 95% diet and 5% exercise. So how much exercise is needed? # of mins per day? # of days a week? I work out 6 days a week, alternate with cardio and weight training.
If we’re talking about losing weight, then in theory, no exercise is needed. You could do it 100% just with diet. But that would be unhealthy as a general lifestyle. If you work out 6 days a week, and you enjoy it, and feel good on it, then great! No need to change what is working for you. You can simply focus on diet.
Thank you, yes it is about fat loss. I enjoy working out, but this flexibility makes me feel very relieved and less guilty on missing a day. Now I will be able to reduce the number of days and/or mix it up with yoga, pilates, cardio and weight training.
Sounds good Aarti! Sometimes exercise can actually be problematic for weight loss (which sounds counter intuitive). But essentially, if you’re following a controlled diet, and then you do a hard workout, it increases hunger. This could then mean you overeat vs your desired dietary goals. Doesn’t the workout mitigate the extra food? That depends if it was an extra piece of chicken and rice, or it was an extra bowl of ice cream and cake (if you know what I mean).
Great summary and great answers to all of the comments – thank you!
Weight loss is my goal,but once the goal is reached and maintained should the fasting every second day be continued or should it end and be something to do every once in awhile? I guess what I am asking is, is the fast now a part of your lifestyle?
Thank you so much!
Hi Canada, thank you for your kind words.
That’s a good question, and it’s one Jason didn’t specifically deal with in the book. In part, this is because he’s suggesting fasting as a way of life, rather than as just a temporary weight loss tool. That being said, I don’t think he’s suggesting the 24-hour or 36-hour fasting protocol as something everyone sticks to forever. Here I’ll quote a direct section from the book:
“The last and most important tip is to fit fasting into your own life! Do not limit yourself socially because you’re fasting. Arrange your fasting schedule so that it fits in with your lifestyle. There will be times during which it’s impossible to fast: vacation, holidays, weddings. Do not try to force fasting into these celebrations. These occasions are times to relax and enjoy. Afterwards, however, you can simply increase your fasting to compensate. Or just resume your regular fasting schedule. Adjust your fasting schedule to what makes sense for your lifestyle.”
What I take from this is that Jason’s trying to open us up to a world where fasting is a possibility – rather than seen as a form of starvation to be avoided at all costs. But how we choose to use this tool of fasting, is down to us as individuals.
Here’s a scenario that could work for some people:
This will need experimentation on an individual basis. Hope that helps!
Dear Alex
Thank you for the time you took to throughly reply. It helped a lot. What you said makes sense. I am giving fasting a go and once I get to my goal I will re-read your suggestions and go from there.
You really know what you are talking about. Do you have a science background? You analyze and simply state so much very clearly. It is very much appreciated.
Thank you again.
Canada
A doctor recommended this book to me, and I read it but this is so helpful. From your understanding, is it important that I fast every other day, or could I start out by picking 2 days each week to do a 24 or 36-hour fast? Thanks!
Hi Rachel. Yeah, I’m sure Jason would back you on doing 1 24-36 hour fast per week if that’s all you can manage at this time. That’s still quite a considerable dietary change compared to eating multiple times per day, on a daily basis.
This is great for my partner but not for me my blood suger levels drop when i dont eat any answers for me to use this
Hi Chris. Could you give more details/specifics on what you mean around blood glucose levels dropping when you don’t eat? It is normal for blood glucose levels to drop between meals, but I presume you’re saying this has negative effects for you – just not sure what exactly.
Chris asked exactly what i was going to ask but I don’t see a followup. I can go about 2-4 hours in the morning with just coffee but then I get light headed and ravenous. I really, really want food by that point. I usually eat a protein like a one egg omelet with mushrooms and cheese to tap down the feeling but then it often (not always) triggers even more hunger and I end up doing a bit of a binge. I never eat processed food and rarely sugar, but the fasting beyond a few hours seems to impair my brain, makes my stomach grumble and triggers binge eating. Is this a sign I might already have problems regulating insulin? I am about 35lbs overweight and most of it came on after menopause; although, I have always had to watch my weight and gain easily.
Out of interest, what is your day-to-day blood glucose level? And how long after eating a meal does it return to baseline?
Thanks for the quick response. I have no idea what my blood glucose level is. How do I test that? Sometimes I eat and I feel fine for a 2-3 hours but I often get the urge to snack. I used to keep weight off eating what is basically the Atkins Diet but over the years for environmental reasons I’ve been eating less meat. I still tend to eat tree nuts, apples and proteins (eggs. salmon) to stabile my blood sugar but I’m what most people would call “a grazer” and eat small things frequently. I’ve started doing it thinking the habit was stabilizing my blood sugar and to prevent binging. However, now it seems like it just has created a cycle of frequent eating and too many calories in a day. I often go from feeling very hungry to feeling overfull quickly, but then hungry again within two hours. This pattern has gotten worse as I have gotten older and now I’m almost 60.
To test your blood level, you can use a blood ketone meter. Same ones diabetics use. Compare it with normal ranges before and after eating, and see where you are. At least that way you’ll know if there’s an actual issue with your blood sugar.
I reduced my calories to about 1200 cal a day and gained 22 lbs and became prediabetic. It was a shock to me. I felt out of control! After reading Dr Fung’s book, I have lost 23 lbs over a year and now know how to control my weight with intermittent fasting. I am good with when to eat and when not to, but have some confusion about some major food types including dairy, meat, and in-refined carbs. I do want to know if sugar free gum and drinks cause insulin spikes? I still don’t know why I became prediabetic when I had virtually cut out all sugar, but did chew sugarless gum to deal with hunger pangs and drank some sugar free drinks to keep hydrated, but mostly sweetened with stevia. I KNOW I am on the right path and it is wonderful to be the captain of my own ship again. I wish all endocronologists would read this book. I was only offered drugs by my doctor.
Hi Elisabeth, thanks for sharing your experiences. I’m glad to hear you’re having success.
With regards to your question – do artificial sweeteners cause insulin spikes?
It would appear there’s at least some evidence that this is the case. This study showed an increase in insulin when consuming sucralose:
It also appears that sweeteners affect the gut bacteria, which could have negative consequences on metabolic health.
Can I still have a post workout protein shake 3 days a week? I have a protein powder called Carnivore that’s made from beef instead of Whey. I’ve also found powders made from bone broth. It’s only after lifting weights which I do 3 days a week.
Yeah, shouldn’t be an issue on non fasting days.
Hi Alex, just came across your summary is actually pretty good.
Ive read the book.
Thanks
Thanks Diana 🙂
Hi I’ve come across your comments and Jason Fung ..iv spent 30 years battling weight and pcos I’m forever tired and stressed… With 2 kids I’m wall falling all the time…plus I’ve spent a small fortune on weight loss classes to loose only to gain twice over… Pcos is my problem I’d say can this diet help and get rid of weight once and for all… I’m so fed up and low over my weight and other pcos problems is it worth buying the book please help
Hi Katie. The main crux of Jason’s book is about fasting (rather than diet itself) – and using long breaks in eating to improve insulin sensitivity (and then as a result, overall health). This may be something you want to look more into.
There is a Facebook suppport group for people following dr. Fung’s advice. I saw a similar story to yours a few days ago on the support group. Dr fung’s method was working for this fellow pcos sufferer even though nothing else ever had for this person. Good luck!
Wow so the way I see it you basically can eat anything but cut back on high carbs and avoid sugary food it’s the fasting that will help you lose weight. After reading what you’ve written it makes me feel better as I can’t have to much fat as it affects my ulcerative colitis (UC) but I have diabetes as well and carbs helps with my UC but not my diabetes but if I can still do some carbs and add protein to support both my health issues it should work. So glad I found you site makes sense now to put it into practice.
Hi Anne, thanks for the message. Sounds like you’ve nailed it. That to me, is one of the real benefits of fasting (both intermittent and prolonged). The ability to be less militant about restricting carbohydrates, but still be able to burn fat. Thus shedding excess fat + reducing insulin resistance.
I’m currently working my way through Jason’s other book; ‘The Diabetes Code’. The solution is essentially the same as in this book; avoiding processed and sugary foods + fasting. But the cool thing with the Diabetes Code is he goes deep into the mechanism by which diabetes occurs. Although that also means its a slow read if you want to absorb it all.
Jason’s protocol favours 24+ hour fasts, which is fine. But the other thing you could think about integrating is intermittent fasts. You could try the 16/8 protocol, so 16 hours fasting 8 hours eating window. Or you can go slightly more extreme (which I’m experimenting with currently), at 20/4, so 20 hours of fasting, 4 hours eating window.
Good luck on your journey, and if you feel inclined, let me know how it goes.
Hi,
I’m curious if the fasting days could have fresh green juices with no fruit. Example Celery, spinach, ginger and lemon?
Hi Lisa.
The mix that you’ve mentioned would indeed be super low in carbohydrates (which are essential to avoid when doing this fast), so I don’t think it would be a huge issue if you opted to do that.
That being said, of course avoiding all food would be more ideal. And then anecdotally, from my personal experience, I find that adding just a small amount of food can actually make you more hungry not less. It could be psychological, it could be related to the digestive system getting fired up; I’m not sure. You might be different though.
But yeah, all that being said. If this green juice is the difference between you fasting, and not fasting at all, then go for it.
Hi
HOW this fasting diet is not going to slow my metabolism? how do I check that out?
Hi Betty, its a good question, with a relatively long answer.
At a high level the answer revolves around two points:
Of course, you can imagine with a long enough fast, the body will be forced to decrease its basal metabolic rate (the amount of energy it expends for survival). But with the method we’re talking about, where we alternate between fasting and feeding, we won’t see a big metabolic reduction. And what we will see, which is absolutely key, is the body switching over from burning glucose, to burning fat.
Hope that helps answer the question.
Any tricks to not feeling sick during the fasting days? Does it get easier?
Hi Jessica – so firstly, yes, it definitely becomes easier if you can get through the first few attempts.
That being said, there are a couple of things that come to mind that may help.
1) If you don’t already; reduce carbohydrate consumption and increase healthy fat consumption (avocado, avocado oil, olive oil, grass fed butter, coconut oil, nuts, cheese & yogurt (in moderation) etc). This helps your body become less reliant on glucose and become more fat burning adapted.
2) If you’re really struggling during the fast you can try adding MCT oil, specifically caprylic acid (C8), which helps raise your blood ketones, and can reduce hunger + increase energy whilst fasting. See this post on Tim Ferriss’ 3 day fasting method – where he suggests this technique.
3) On non-fasting days, you can experiment with time restricted feeding (aka intermittent fasting) – so essentially you aim to eat within a 8-10 hour time window. Again, this encourages the body to adapt to fat burning.
4) If you’re not already getting enough, try adding electrolytes during the fasting day. One brand whose capsules are good are Salt Stick. This can ease discomfort that sometimes occurs when fasting.
Appreciate not all of these will be applicable, but perhaps there’s something from the list that helps. After a while the fasting does indeed become more “normal”, but it takes a bit of time.
Thank you so much for this. I’m halfway through the book and it’s just blowing me away. You make it easier for those of us not in the med profession. This is bar far the best resource I’ve found that compliments the book.
I’m planning to start in a few days. With regards to fasting. Is it okay to fast daily or during the weekdays instead of every other day like in the model?
Hi Jaclyn, thanks for the message, glad the post is helping.
With regards to your question; “is it okay to fast daily or during the weekdays” – I wasn’t sure what you meant.
Do you mean you want to fast multiple days back to back? If you could clarify, I’m happy to try to answer the question.
Is there a guideline as to how much carbohydrate can be eaten on non-fast days? It might be very easy for me to eat too much of beans and whole grains. BTW, he doesn’t mention brown rice. OK?
Hi Elizabeth, thanks for the comment. With regards to Brown rice, yes, no problem.
With regards to guidelines for carbohydrates on non-fasting days. Jason specifically avoids being prescriptive on this part. His intention is that as long as you’re avoiding the nasties like cakes, candies, cookies, deserts, any foods containing sugar etc. then you’re okay to eat as you please, and let the fasting phase of the diet do the heavy lifting vis-a-vis losing weight.
All that being said, if you do find you reach a plateau after you’ve been following the diet for a few months, then yes, reducing carbohydrates on non-fasting days should help to overcome that. Assuming you’re doing everything else correctly already.
Thanks for your information. I am in the middle of the book.
Is water ok to sip on all day or only at meals? Also, I don’t drink coffee but I like to add powdered packs to flavor my water. Is this an issue?
Hi Lisa, thanks for the message. There’s no restriction on drinking water. With regards to the powdered packs you add to water – I’m not familiar with those. Whilst you’re fasting, I’d encourage you to try to stick to water, bone broth and tea if you can. If that’s not an option, and the powders are a must, then just make sure they don’t contain any sugar or calories whilst you’re fasting.
*sigh*
Like every other diet, the “Obesity Code” claims to have some magic secret that nobody else has ever figured out… and then recommends a diet of less than 1,000 calories a day.
Yeah, see, you could eat Snickers Bars and lose weight that way. In fact, a guy HAS eaten Snickers Bars and lost weight, just to prove a point. The only value any of these cult diets have is that they can (temporarily) get their followers to eat fewer calories, under the the delusion that they’re really doing “something else”, like “resetting their insulin levels”.
At the end of the day, there’s nothing magic about weight loss. Eat fewer calories than you burn, and you’ll lose weight.
Hi James, thanks for the comment.
Actually this subject is tackled very specifically in the book, with quite a number of pages devoted to correcting the misunderstanding.
There are a number of reasons why boiling weight loss down to “calories in, calories out”, is the wrong direction to go in.
I’ll mention two of the key arguments – but to do Jason’s argument justice, it’s worth reading the book.
Firstly, the idea that “a calorie is a calorie” is incorrect in the context of our bodies metabolism. Fats, protein and carbohydrate all trigger different hormonal responses within our bodies. In particular, glucose molecules will require our body to increase its circulating insulin. And insulin is the primary fat storage hormone.
Secondly, when we restrict calories, our bodies generally down-regulate their energy expenditure. This is problematic if we’re trying to lose weight. This is one of the reasons that Jason encourages fasting + not restricting calories for meals. The idea is that the fast does the heavy lifting for the weight loss, but when you re-feed, you re-feed enough such that your body doesn’t feel the need to restrict energy expenditure.
Hope that helps – pick up the book for more details.
You clearly have not read the book. He does not recommend a diet based on caloric intake so the less than 1000 cal a day is completely untrue. He also completely debunks the theory of calories in vs calories out. That’s the whole point of the book! Hormonal regulation of obesity and NOT calories. Recommendation – read the book before you comment.
You must’ve missed the main message of the book. Your body doesn’t react the same to all calories. Actually read the book.
Hi, so on days that I’m not fasting can I still eat stone ground bread or tortillas or try to consume less of that as well?
Hi Patricia, thanks for your comment.
Regarding bread and tortillas on your non-fasting days, you can indeed eat them. But yes, as you say, try to minimize the quantity of them where possible. As for maximal weight loss it’s optimal not to consume too many carbohydrates.
Hello! I have a question.. as someone who does not drink caffiene, i notice he has a LOT of it in this plan (coffee and green tea). Is this a crucial part of the plan?
What do I do (or where do I go to ask) about this question?
Thanks!
Hi Kyla, good point about all the tea and coffee.
I’m the same at the moment, have cut out caffeine.
With regards to the diet plan, you can definitely cut out all the tea/coffee and it won’t have any effect on the benefits.
As long as you’re adhering to the fasting window (the full time spent fasting), that’s the main thing.
My guess is that Jason added the hot drinks on the assumption that most people consume them, and to give the plan some content. He hasn’t added them because he wants us to increase metabolism through caffeine, or anything like that.
Hi,
I have been following the eating plan for 4 weeks now and have more energy than ever and have dropped 22 lbs. I seem over the last week to have hit a plateau, any suggestions to help break that.
Hi Heather. A couple things come to mind for breaking your plateau:
Neither are particularly fun, I accept that. But they are two things most likely to help.
It probably makes sense to try replacing the carbohydrate calories with fat calories, before you start cutting down on calories altogether.
Certainly appreciate the time and effort you’ve put into this. Seeing a seven day food plan laid out has been enormously helpful. You rock!
Thanks for the summary. I’m currently reading the book and am only on page 70. He ha spent a lot of time driving the point home that a reduction of calories (the go to diet for most Americans) will result in a reduction in basal metabolic rate and that when the diet inevitably fails the weight comes back on quickly.
So I’m looking at those sample meal plans and I can’t help but think that they represent a drastic reduction in calories for nearly anyone. Does he reconcile this at some point? These are meal plans for life? If so, I fail to see how they are not the same, or worse, than any other low cal option. Sure, the macro ratios may be different than some but there are programs like Body for Life with similar macros.
I’d love to read what your takeaway is on these points.
Hi Mike. I understand your point. I think with the meal plans they are more about providing an example of meal timing alongside fasting timing. Structure, if you like. Maybe that needs to be made clearer, good point.
The plans don’t mention a calorie or quantity limit on the amount of food consumed.
I would probably suggest to adapt the meal plans so that they provide enough calories to meet your satiety level. Then see how the fasting affects your body composition, and fat loss (if that’s a particular goal).
I’d imagine what would happen, is that the time spent fasting will increase the amount of fat your body burns. And if you have weight to lose, you will lose some.
Then, if after practicing this for some weeks/months, you reach a plateau, you could then experiment with adjusting the calories, or, macronutrient composition of your meals to see if that breaks the plateau.
If fasting alternate days for the foreseeable future sounds unnapealing. Then Jason’s fasting method could just be used as an initial catalyst. Once you meet your health goals, you could test out moving to time restricted feeding (also called intermittent fasting).
There have been studies suggesting positive health benefits with 14/10 and 16/8. So fasting for 14 hours and eating within a 10 hour window.
Time restricted feeding will still give your body time to tap into it’s fat stores, and provide some of the benefits of fasting, whilst also being more compatible socially, and easier to follow long term.
My personal approach is time restricted feeding 14/10, with (approximately) quarterly water fasts or fast mimicking diet.
How would you fit in High Intensity Interval Training (HIIT) into this diet schedule? I work out in the morning with a very HIIT workout for one hour 2-3 times per week and don’t want to give that up.
Hi Renee. Yes, can understand your hesitation doing HIIT whilst fasting, as you could feel weak, hungry and tired for the rest of the day if you can’t eat. It would make most sense to do the HIIT on your “eating days” and then avoid it whilst fasting.
This is so helpful, thank you! I noticed one breakfast includes bacon/sausage, but the book advises against processed meat. What are your thoughts about turkey bacon (in moderation)?
Hi Alexis. Great point! That’s actually pretty funny, Jason both warns against eating processed meats, but then mentions sausage meat in his meal plan example. Not sure how to remedy the discrepancy, as it’s hard to imagine sausage as anything other than a processed meat. Perhaps there’s a healthy sausage recipe if its hand-made, but that would be unusual! In terms of turkey bacon in moderation, I can’t see that being a big issue. It’s thought the preservatives used in bacon aren’t particularly good for us, but hopefully in moderation they’re not too bad.
Hi, I’m just starting the fasting. I get so hungry, I snacked on cahews. But you say stop snacking. What should I do when I really feel hungry?
Thank you
Erin
Hi Erin! Good question. Personally, I found that fasting is a skill, and that one improves over time. Both in terms of the bodies adaptation to fasting, and the mental “strength” it requires. It’s definitely not easy, and I wouldn’t expect to be a pro at it right from the start. I would suggest building up the fasts bit by bit, and not beating yourself up if you don’t make it through 100%. Assuming you keep at it, you should get to the stage where fasting for 24 hours is achievable, and then you can move on to a longer time period if you want.
Thank you so much for taking the time to write this summary!
Thanks for the summary. I am listening to the book a second time, but this give me good info I can carry with me.
On fasting days, can I take OTC pain medication (Aleve, Tylenol, Excedrin, etc.) without affecting the benefits of the fast?
How long do you fast before you need to start worrying about your salt intake?
Hard to say exactly, because it will likely vary based on the person/climate/daily activities. But I’d imagine it should only really become a potential issue going beyond 24 hours.
I’m a coffee lover! I love decafe coffee with half and half. Is that ok? Plus is there any fruit or vegetable you can’t eat? I’m hoping this works
Hi Kelley! With regards to decaf coffee with half & half… presumably the question is, whilst fasting, is it okay to drink that? Technically speaking, if you were being strict, you’d want to cut out the half & half milk, and just drink black coffee. Some might argue you even just drink water. However, I think pragmatically speaking, your weight loss won’t be affected by a few decaf coffees with milk. If that’s all you consume during the 24 or 36 hour fasting periods, that should work as planned.
Regarding fruit and vegetables – the main point there would be to avoid too much sugary fruits. For example, 1 apple a day is fine, but having lots might slow down the weight loss. Also, avoid fruit juices, again too much sugar.
Instead of half and half use heavy cream–heavy cream has no carbs whereas half and half does.
Can the order of meals be rearranged – my wife works late would like meal in the middle of the day.
Hi Shawn. Yes I think meal order is flexible, as long as you’re able to get 24 hours (if doing the 24 hour fast version) of fasting in. A possible way to build up slowly would be try to try intermittent fasting. Something in the order of 16 hours fasting and 8 hours in which you allow yourself to eat. 16/8, or even 14/10 (14 hours fasted, 10 hour window for eating) is a good start.
Do you know whether you are able to drink unlimited amounts of green and herbal teas?
Hi Barbara, thanks for the comment. Yes, there is no reason why you can’t drink a good amounts of herbal teas, even whilst in the fasting phase. Green tea does contain caffeine though, which can affect your sleep quality (even if you don’t notice it), so usually is best consumed earlier in the day. Leaving the evening for caffeine free herbal teas such as mint, rooibos, camomile etc.
I’m encouraged to try this plan. We’ve been following a plant based diet for a year with little success with weight loss. My cholesterol is elevated after a year off medication & of plant diet – eliminating fats, dairy, sugar, processed foods. My husband is DM2 and takes Levimir and oral med – his blood sugar is improved but weight elevated.
How does this fast diet work at reducing cholesterol and balancing blood sugar? How does he fast while on insulin???
Hi Losey. Thanks for the comment.
One of the issues with a plant based diet and weight loss is that often a plant based diet ends up being high in carbohydrates. Even when you cut out simple carbohydrates like sugar.
Carbohydrates stimulate insulin, and insulin is our energy (and fat) storage hormone.
This particular method mentioned by Jason Fung works by reducing insulin secretion during the fasting period. Thus your body burns its fat stores whilst fasting.
It can improve blood sugar levels by decreasing your cells insulin resistance (again this happens during the fasting phase).
Regarding your husband and fasting, I would honestly recommend consulting a doctor who understands the complications of his medical condition and the medication he is taking.
It’s quite possible that he needs to adjust his medication while he’s experimenting with the diet, and thus you’ll need to be in commmunication with a doctor to manage this safely and effectively.
Just as one simple example (although there are many more), someone fasting won’t need as much exogenous insulin whilst they’re fasting. And thus injecting a “normal” amount of insulin whilst you are fasting could result in hypoglycemia, which is very bad.
I don’t mean to scare you from testing this out with your husband, but I just mean to say that it’s a complicated issue and you would need to work with a doctor to understand the best way to approach it.
I just ordered the book and haven’t received it yet. I have Hashimoto’s thyroiditis. Should I expect the same results as someone who does not have this problem? I have found I have picked up some pounds going through menopause too.
Hi Connie, I would be cautious with the fasting if you have Hashimoto’s. Of course, ideally, run your diet plan by a healthcare professional first to see if they have any concerns. In particular I’d be wary of any medications you’re on, and what effect fasting could have on them. In the interim before speaking to your healthcare professional, google hashimoto’s and fasting, and see what other peoples experiences are. That may arm you with enough knowledge to have a more informed conversation with your healthcare professional.
Thank you for creating this lovely summary Alex. Very informative and clearly written.
Thanks Julie! Appreciate you taking the time to leave a comment.
If you do seeing anything you’d like further info on, let me know.
I am a lacto-vegetrian; which means no eggs as well. What are my options for protein? Are legumes/lentils allowed?
Hi Mina, yes, Jason discusses legumes in the book, and they are allowed. And of coures, lentils are a legume, so they are allowed also.
What would be a good vegetarian substitute for eggs?
Hi Mina.
You could look at using a few different high protein vegetarian foods, such as:
And that’s just a taster really. There’s a lot of good options. But I appreciate it takes a bit more work than just eating a couple eggs.
Thank you Alex. I feel better after seeing the these choices.
Are tofu and paneer(Indian cottage cheese, homemade, no additives) okay to consume?
Hi I bought the audible version of this book so it’s hard to look up certain things. I wanted to know about dairy products…milk, cheese, etc…
What about Dairy? I have read the book and it states you can eat full fat dairy and I see milk and goat cheese on the 7 day plan but its not much. What are the best dairies to eat? full fat cheese, whole milk, ??
Yes, Jason doesn’t advise against full fat dairy (as you say). You mention full fat cheese, to add to that, grass fed butter is also a good option. Typically grass fed butter is lower in omega-6 fatty acids. Brands that are grass fed include Kerrygold. I personally try and buy butter than doesn’t have salt added, otherwise I find it easy to over consume.
isn’t it amazing a dietician told me eat more often 6 times a day because if I didn’t eat my brain goes into “i must reserve food mode” and doesn’t burn it off. Will get the book and go for it
Yes exactly, if you don’t stop eating, you won’t give your body much of a chance to burn fat.
Hi. I’m excited about this book because my Dr read it and has lost about 20 lbs in 3 weeks. He is into sports medicine and is athletic. He started gaining weight even though he cut calories.
I’ve been saying this for decades. Counting calories does not work.
I will order the book, but I feel anxious that there is no list of foods that are acceptable to eat.
Hoping that when I get the book that there will be guidelines or ideas as to how to choose.
Ie: are black beans okay? Peas? Carrots? How much fish may i eat before it’s too much?
I wonder how long it’s been since you checked this blog. Hopefully i can get answers. Thank you for your time.
Hi Patricia, thanks for the message. That’s great news about your doctor’s success.
With regards to your questions about black beans, peas and carrots – there’s nothing in Jason’s book that suggests they would be anything other than good. His core focus on the diet section is to cut out sugary foods and encourage us to stop snacking between meals. Real foods that have been eaten by humans for centuries, such as the ones you mentioned, are all ok to eat.
With regards to “how much fish may I eat before it’s too much” – he hasn’t addressed that specifically that I’m aware. At a rough guess, assuming you’re following Jason’s fasting protocol, it should be ok to go wild and eat upto a whole plate full of fish if you so please. As long as you’re doing the 24 to 36 hour fasts every other day (as highlighted in the post), you should see good results in terms of weight loss.
If you want to dive a bit deeper into the topic of protein consumption – Valter Longo discusses in his book “The Longevity Diet”, that up to the age of about 70 we should minimize protein consumption. That’s because it increases IGF-1 secretion, which is linked with cancer. Once you hit 70, increasing protein is healthy because it helps maintain dwindling muscle mass – which can lead to injury in older people.
Hi – I am Jayshri. I would like to follow this fast, but I only eat chicken …. is there a way we can substitute the other meats for something else. I do not mind vegetable options. Thank you.
Hi Jayshri, yes replacing the meats with vegetarian alternatives would be no problem. The key aspect are the fasting stages, which need to be adhered to in order to achieve maximum results.
Thank you
Nice summary – I’ve read most of the book buy need to remind myself of these key principles 0 thanks