Health
by Jason Fung
Why does dieting keep failing?
Jason Fung is a Toronto kidney doctor who saw the damage type 2 diabetes did to his patients. In The Obesity Code he asks why the standard advice, eat less and move more, so rarely keeps weight off. His answer is hormones, especially insulin.
Hear a sample · read by Laura
Fung argues that obesity is a hormonal problem more than a calorie problem. Insulin tells the body to store energy as fat, so in his view, whatever keeps insulin high keeps weight on. It's the heart of the book, and many obesity researchers dispute it.
Fung describes a body set weight, a level your body defends the way a thermostat defends a temperature. Eat less and it burns less, leaving you tired and hungry. Eat more and, up to a point, it burns more. He believes insulin is what sets the dial.
Fung is all for exercise and what it does for your heart and mood. But he argues it's a weak tool for losing weight, partly because it makes you hungrier. Many researchers agree with him that diet does more of the work.
Fung argues that constant snacking keeps insulin up all day, so he's against grazing and sees no special need for breakfast. That leads him to intermittent fasting, the most contested part of the book. It isn't safe for everyone, especially people on diabetes medication.
Hormones
Fung argues weight gain is driven by hormones, mainly insulin, more than by calories.
Calories
Cut calories and your body burns less to match, which is why diets stall.
Insulin
High insulin tells the body to store fat. Keep it low and the body can burn it.
Sugar
Cut back on sugar and refined flour. They push insulin up the most.
Snacking
Stop snacking. Eating all day never gives your insulin a chance to fall.
A story from the book
During the Second World War, the scientist Ancel Keys cut the rations of young volunteers for months. Fung describes what followed. Their bodies burned far less energy, they felt cold and weak, and they thought about food constantly. Once the experiment ended, the weight came back fast.
Hot take · true or myth?
Sugar is fattening only because of its calories.
Myth. Fung singles out sugar, especially the fructose in it, which he says loads the liver and drives insulin resistance. Cutting added sugar is the first step in his plan.
One thing to try
This week, swap one sugary drink a day, like a fizzy drink or a juice, for water or unsweetened tea. Cutting added sugar is the first step in Fung's plan, and most doctors would back it. For anything bigger, talk to your doctor first.
Knotd has the key ideas from 250+ non-fiction books, each in a few minutes, in plain words. The Obesity Code comes with a Hot Take round to make it stick.
Get the whole book on KnotdOpen in the appWhy does dieting keep failing? Jason Fung is a Toronto kidney doctor who saw the damage type 2 diabetes did to his patients. In The Obesity Code he asks why the standard advice, eat less and move more, so rarely keeps weight off. His answer is hormones, especially insulin.
Fung blames insulin; The body's thermostat; Exercise won't do it alone; Why he cares about timing.
This week, swap one sugary drink a day, like a fizzy drink or a juice, for water or unsweetened tea. Cutting added sugar is the first step in Fung's plan, and most doctors would back it. For anything bigger, talk to your doctor first.
Yes. Knotd has the key ideas from The Obesity Code in a few minutes, in plain words, plus a Hot Take round to test them. It's one of 250+ non-fiction books in the app.
