The Obesity Code
© 2016 Jason Fung
Jason Fung begins with a question: why are there fat doctors? If the conventional analysis of fat and its prescription are accurate, why do many people struggle to make long-term headway against obesity? The Obesity Code argues the case against the caloric model, presenting its own: obesity is a multi-factorial disease, one whose chief driver, insulin, is sorely unappreciated. Related to Gary Taubes’ work arguing for the hormonal model (Good Calories, Bad Calories; Why We Get Fat; The Case Against Sugar) and others, The Obesity Code wraps up with advice for attacking fat by land, air, and sea. Those trying to understand the challenge of obesity, either for personal or social reasons, will find it a helpful resource — though one marginally diminished by its breeziness.
Fung begins by dismantling the caloric model, both in theory and in practice, evaluating numerous studies which demonstrate the inadequacy of the calories in, calories out approach. The body responds to a drop in its caloric intake the same way those of us not holding political office respond to a drop in our income; it spends less. Those who attempt to eat less than they need, at the same time trying to increase their activity, will find themselves beset with misery and cravings. The crucial misstep in the caloric model is that it misses how fat is regulated by the body — every body, regardless of age or health. Hormones drive the creation, dispersal, and use of fat, whether the case is girls developing curves in middle school or both sexes fighting the pudge amid their freshmen years in college. Although the main manager of fat is insulin, Fung points to several other factors, notably cortisol — a stress hormone that, if consistently present in the body, reliably drives weight up.
Because the lion’s share of weight problems are driven by by how modern diets interact with the insulin cycle in our bodies, Fung devotes more attention to that factor than any others. He uses an interesting example of money management to explain how it works. After a meal, your body is flush in glucose and insulin, the latter of which has emerged with one job: to get the glucose where it needs to be. That will be into your cells, at first, but you don’t need that much energy at one time, so it converts the glucose into glycogens, which it stores in the liver. Fung likens this to a wallet: it’s easy for insulin to move glucose in and out of the liver. Wallets, though, have limits to how much they can hold — and so insulin creates fat to store the rest. Because people in the modern world never stop eating, we continually keep the short-term storage filled to capacity, and the fat stores…..are never touched. If someone truly wants to lose weight, they need to give their bodies time to empty the short-term storage and then begin using the long-term. This will not happen if they snack throughout the day, even if they’re just sipping a diet soda: artificial sweeteners may not have calories, but they still summon forth insulin hormones to patrol around looking for glucose to store, and so long as insulin is around, it’s not letting your fat escape. Fung advocates the practice of intermittent fasting (which can be something as simple as a no-snacks rule to reducing eating windows in a given day, to extensive multiday fasts) to address the insulin problem head on. He’s written extensively on fasting’s application for both obesity and diabetes.
The Obesity Code is not a rehash of Gary Taubes’ work, though, because Fung addresses more factors — cortisol, for instance, and the body’s sleep cycle, and considers various kinds of diets. There are several diets that work within the hormonal model, like Atkins and Keto, but following a specific diet in perpetuity is difficult for most people. There are some items that should be avoided, like sugar and highly processed foods, but regulating the when of our food intake is more important than banning or promoting whole classes of macronutrients. Yung partially echoes Michael Pollan’s food rules: Eat real food, not too much of it, and mostly plants.
1. Reduce your consumption of added sugars. 2. Reduce your consumption of refined grains. 3. Moderate your protein intake. 4. Increase your consumption of natural fats. 5. Increase your consumption of fiber and vinegar.
More importantly, however, he asks the reader to consider the virtues of current political and medical practices in the light of the hormonal model’s accuracy. If the hormonal model is true, then Americans are being taxed to provide subsidies to the very companies growing products destroying our health; and even more disturbingly, if the model is true, the conventional treatment for type 2 diabetes will only lead to its growing progressively worse, and inducing obesity in the bargain.
I began reading The Obesity Code merely as a reminder for what I knew: I dropped a lot of weight in a short amount of time back in 2011-2012, and Taubes and others were the ones who helped me make sense of how that had happened.* Yung’s work proved far more expansive than I figured for. While Gary Taubes’ work is more professionally presented (Yung has a casual style), there’s no denying the amount of useful content here. I can well understand its positive reception among those seeking to understand obesity both personally and as a medical crisis.
* In autumn 2011 I was diagnosed with hypertension. I was still looking for work and couldn’t afford to stay on medication, so I changed my diet to avoid high-salt foods, and began neighborhood walks because exercise was supposed to be combative as well. Starting from the high 300s, I dropped down to 206 thanks to a diet very low in processed foods. I blame Mexican food and IPAs for never being able to crack the 200 barrier — I love tacos al pastor more than I love the idea of being in the hundred club.