Chapter 19 | What to Eat

Oct 21, 2019


Check out a replay of the Facebook LIVE discussion about this chapter HERE

You Will Learn

  • What causes high insulin levels.
  • The multifactorial nature of obesity.
  • Dr. Fung’s 5-step plan to improve your nutrition. 


About Dr. Fung, Author of The Obesity Code and The Diabetes Code

Dr. Jason Fung is a medical doctor, nephrologist by trade, who specializes in kidney disease, type 2 diabetes, and obesity. He acknowledged that traditional medicine wastes time and resources attempting to treat symptoms of disease, rather than the cause of disease. 

You can purchase The Obesity Code book HERE


Overview of the Book

Here is the outline of the book. This post covers chapter 19 in Part 6. 

Part 1: “The Epidemic,” explores the timeline of the obesity epidemic and the contribution of the patient’s family history. It highlights the underlying causes of obesity. 

Part 2: “The Calorie Deception,” reviews the current caloric theory in depth and highlights the shortcomings of the current understanding of obesity. 

Part 3: “A New Model of Obesity,” describes how hormones are involved in the development of obesity. These chapters explain the central role of insulin in regulating body weight and describe the vitally important role of insulin resistance. 

Part 4: “The Social Phenomenon of Obesity,” dives into childhood obesity and why obesity is associated with poverty. 

Part 5: “What’s Wrong with Our Diet?,” explores the role of fat, protein, and carbohydrates, the three macronutrients, in weight gain. In addition, it examines one of the main culprits in weight gain - fructose - and the effects of artificial sweeteners. 

Part 6: “The Solution,” provides guidelines for lasting treatment of obesity by addressing the hormonal imbalance of high blood insulin through proper nutrition, sleep, and stress management. 


“All Diets Work...All Diets Fail”

To understand this saying, it’s important to understand that obesity, like most other diseases, is multifactorial, meaning there isn’t just one cause. This is one of the reasons there is so much conflicting information. People talk about low-fat, low-carb, low-calorie, high fat, etc. Most diets have more in common than different, but agreement doesn’t sell. 

That is why most diets work. At least in the short-term. 

As Dr. Fung explains on page 218, “the truth is that there are multiple overlapping pathways that lead to obesity. The common uniting theme is the hormonal imbalance of hyper-insulinemia.” He goes onto say on page 219, “insulin is the major hormone that drives weight gain, so the rational therapy is to lower insulin levels. There are multiple ways to achieve this, and we should take advantage of each one."

Most diets lower insulin in some way. Whether that be eating fewer calories, less starch and sugar, more fat, eat less often, etc. The problem comes when you lose weight below your body set weight. That is when your body will resist whatever diet you are on, stimulate you to want to eat more, and slow your metabolism so that you don’t go below your set point.

For some people, the following interventions will be enough to lower their insulin levels and body set weight, for others, intermittent fasting may need to be used to help insulin levels drop even lower. Meal timing and fasting will be covered in the last chapter, When to Eat. 

It is important to determine what is causing an individual’s insulin levels to be high and make recommendations accordingly.  

Usually it is not just one reason. Here are the most common reasons: 

  1. High refined sugar and starch intake, sometimes unknowingly. 
  2. Grazing throughout the day. 
  3. Chronic stress. 
  4. Chronic sleep deprivation. 
  5. Medications that have a side effect of high blood sugar. 
  6. Genetics.

The takeaway point here is that if you want to lose weight for the long-term, you will likely have to change more than your nutrition, and it can't just be a "diet," it has to be a lifestyle change. It can take years to get healthy, even longer to solidify those habits, and that is okay. Be patient with yourself, give yourself permission to fail, then get right back up and try again. 


The Multifactorial Nature of Obesity

I’ve said this before but will say it again. Obesity is not a special disease. It is not caused solely from eating too many calories. It will not be fixed by just eating fewer calories. Obesity is caused by persistently high insulin levels, which as I just described above can be caused by a myriad of different reasons. Your body set weight is hormonally regulated just like every other system in your body. 

That is why there is not just one approach we need to take to treat it. We shouldn’t tell people “the best diet is one you can stick to,” which is a common piece of weight loss advice. 

We don’t use the “do what works best” approach for other health conditions and we shouldn’t give that advice to lose weight. Take for example cardiovascular disease. There are a many risk factors that contribute to the development of cardiovascular disease like genetics, smoking, diet, exercise, stress, family history, age, etc. Some risk factors are more influential than others, but we don’t try to pick out just one and say now THIS is the cause of cardiovascular disease. 

The same goes with cancer, Alzheimer’s disease, and type 2 diabetes. Obesity is not an exception. There are many risk factors and preventative behavioral changes that can and should be made to optimize your long-term weight loss success and reduce the risk of developing other conditions. 

As Dr. Fung says on page 216, “what we need is a framework, a structure, and coherent theory to understand how all its factors fit together.”

There is best-practice information out there for sustainable weight loss, unfortunately it is being muddled with all the other outdated, incomplete, and heavily funded marketing information online. There is plenty of scientific research behind what works and what doesn’t.

I believe we should disseminate that information, provide the behavioral counseling and support, and let people make their own choices about if they want to follow-through with the advice. 


Dr. Fung’s 5-Step Plan to Improve Your Nutrition 

1. Reduce your consumption of added sugars

The first point Dr. Fung makes is to reduce your intake of added sugars because the concentrated fructose can contribute to insulin resistance in your liver and the refined carbohydrates can contribute to elevated blood sugar levels and higher insulin levels over time. 

One trick the food companies use is to disguise the word sugar. They may use other words like fructose, dextrose, glucose, sucrose, maltose, etc. This way, the word sugar isn’t listed as the first (and most prominent) ingredient on the food label. 

He points out that asking how much sugar is acceptable is like asking how many cigarettes are acceptable. The less the better. 

He also reminds you to watch our for hidden sugars in sauces which can have a TON. I did a product review and went through exactly how much added sugars (that were hidden) were in popular packaged food items. Check that out HERE. 

He points out to avoid traditional desserts unless on special occasions. I would encourage you even then to limit your portion sizes (which I KNOW can be hard to do since sugar triggers dopamine, the feel good hormone, to be released in our brain so it’s hard not to go back for more). I’d encourage you to structure your meals in a way that you are full and satisfied, and to drink plenty of water. This will help prevent you from overdoing it on dessert. 

If you want to eat breakfast, go for it. If you don’t feel like you need it, wait till lunch. If you are eating breakfast, try to treat it like any other meal and get your nutrition from whole food sources that are minimally processed. For example, if you want oatmeal, make it from scratch verses buying the packs with the added sugar. Avoid the breakfast cereals and bars that are little more than starch and sugar. 

I encourage clients to get protein, fat, and fiber at each meal whenever possible. Cereal may contain some fiber and protein, rarely does it contain enough of the good stuff, more-so just starch, and hardly ever does it contain fat. 

Dr. Fung as you will find out in the last chapter is big on meal timing and eliminating snacking to avoid another opportunity for insulin to be released. Further, many common snack options are highly processed for convenience and high in starches and sugar. If you need a snack, go for healthier options like nuts, cheese, fruits, or vegetables. 

Lastly, he warns against added sugar in beverages. If you want your mind blown, go look up how much sugar is in some of the Starbucks drinks! Also be aware of artificially sweetened drinks as many artificial sweeteners can still raise your insulin levels. See THIS post for more information on how that works. 

Stick with water or sparkling waters. Coffee and tea (without the added sugar) are also excellent choices. He gets into all the antioxidant power of these two drinks in the chapter which was interesting but I’ll skip that detail here. 

2. Reduce your consumption of refined grains

The key word here is refined. 

The problem comes in the refinement and processing that strips the grains of the protective fiber, protein, and fat that helps slow the digestion of the starch.  

Try to significantly reduce flour products like bread, pasta, bagels, muffins, pastries, etc. Think of these products as dessert, they should be eaten sparingly and on special occasions, ideally with other healthier food options to help mitigate the blood sugar and insulin spike the processed grain will have on your body. 

3. Moderate your protein consumption

VERY high protein diets are beneficial for some nutritional or performance goals but weight loss is not really one of them. Protein is a necessary nutrient and Dr. Fung recommends we get between 20-30% of our calories from protein. Remember, this is strictly talking about what is best for weight loss, not necessarily other health or fitness goals. 

4. Increase your consumption of natural fats

Fat cause the lowest insulin release compared to protein and carbohydrates. Check out THIS post to learn more about his previous chapter on which fats are good for you, which are neutral, and which ones you should avoid.  

5. Increase your consumption of protective factors

Fiber and vinegar can reduce the insulin-simulating effects of carbohydrates. Italians will often dip bread in oil and vinegar. So when you have bread on special occasions you can consider using that delicious trick. Vinegar is added to sushi rice which reduces its effect on blood sugar levels compared to rice without vinegar. 

Check out THIS article to learn more about the protective nature of fiber. 

The Final Piece(s)

The last chapter in The Obesity Code will discuss meal timing, specifically fasting. Dr. Fung is a huge advocate for intermittent fasting and I’ll be doing some independent research into this topic further in preparation for that post. 

Don’t forget about the other three important pieces that can influence insulin levels: stress, sleep, and exercise!

Bottom Line

  1. Obesity is multifactorial. Saying blanket statements like eating too many of a certain nutrient is not a comprehensive enough approach to lead to lasting weight loss. That is why many diets work in the short-term but fail in the long-term. We need to assess and address all the factors, nutritional or otherwise, in a person’s lifestyle that may be increasing their insulin and provide the education and behavioral counseling to help change their habits. 
  2. The best dietary change you can make to lose weight is to significantly reduce added sugars, then refined starches. 
  3. Add protective foods to your diet. Eat plenty of naturally occurring fiber, fermented foods, and added vinegar like in homemade salad dressings. 



  1. Chapter 19. (2016). In J. Fung, The Obesity Code: Unlocking the Secrets of Weight Loss. Vancouver: Greystone Books. 

Download My Free Weight Loss Masterclass

This free 55-minute training explains why insulin resistance and inflammation are at the heart of weight gain ... and how to fix them!