"The Obesity Code" by Jason Fung

Review by Borodutch

This book was a wild ride for me! I dedicated a whole chapter of my book to weight loss, and I have lost 44 lbs after trying many diets. For the first third of the book, I thought the author would suggest another dietary sham; I even noted many issues with his theory — but then the book took a turn! And, oh boy, was it a turn! To give context, I can now safely recommend "The Obesity Code" to anyone who wants to lose weight. But first, what are the most crucial points of the book?

  • First, Jason describes the history of various diets, discusses their efficacy, and how they all fail in the long term. This is an excellent summary of the nutritional research so far.
  • Then, the author gradually leads the reader towards the actual issue that makes people gain or lose weight — the insulin levels! It makes sense. Why do hormones regulate every single process in the body but not the weight?
  • Cortisol also raises insulin levels — hence leading to weight gain.
  • Insulin sets the "thermostat" of the body weight, and the body is trying to maintain this set body weight by either gaining or losing weight.
  • More insulin means gaining more weight, and less insulin means losing weight.
  • The main obesity culprit is insulin resistance; when it develops, more insulin gets secreted — and more weight is picked up.
  • Glucose in the blood does not equal insulin in the blood; e.g., protein doesn't raise glucose, but some proteins raise insulin like sugar!
  • Insulin resistance is a slow disease caused by constantly high average insulin levels; e.g., if you eat all day (snacking, for instance) — your insulin will be high all day!

As mentioned above, the first third of the book was questionable. Here are the notes I took:

  • The reasons the author attacks calorie counting are wrong; he mentioned that even "the most disciplined" people — doctors — when counting calories, fail to lose weight. I'm afraid I have to disagree, as I believe that even though the doctors are educated, they are not disciplined. Check out their sleep patterns! Calorie restriction works if every calorie gets counted. Whenever there is a failure with calorie restriction — there is a failure to adhere. Any MD knows that adherence is where most medicine fails.
  • The author mentions Peter Attia in the chapter, which describes that exercise doesn't help lose weight. The overall notion is correct — training does not help. However, I find it hilarious that Peter is mentioned here, as in his latest book, he has pivoted to exercise in his latest book only. This didn't age well (pun intended)!
  • As for the difference between how much people expected to lose/gain during calorie deficit/surplus and how much their weight actually changed — the body is a complex system, and it might as well be that the weight does follow the diet. It simply does so slower than we expect.
  • The author first ridicules the comparison of mice to humans in medical research but then proceeds to cite the study on mice. Seems like the research is only unscientific if it doesn't follow the author's opinion!

But even with all the issues above, I agree with Jason. It seems that insulin resistance is the main obesity culprit. How does one increase the insulin efficiency? Well, reduce the insulin resistance, duh! Here's a good summary of how you can do so. They are not ordered by efficiency, though, and I'd rather you start from the bottom of the list. Exercise helps the least and takes up the most time and willpower. The best way is to reduce the calorie intake, start time-restricted eating intermittent fasting, and cut the freaking added sugar from the diet!

However, like with heart disease — you shouldn't pick just one measure to decrease insulin resistance. As the author says, if your doctor tells you to lower LDL and stop smoking — you don't pick one; you do everything to prevent heart attacks. The same rule applies here — do everything to reduce the effect of insulin resistance if you have extra weight!

And, believe me, I'm lazy as hell — yet I've lost 44 lbs over the last eight years. You can do so too! Read the "Obesity Code" — the advice the author suggests generally works. It might as well be the best book on losing weight I've read so far!