In the book The Obesity Code, Dr Jason Fung debunks many myths regarding weight gain. He explores the real reasons for obesity and provides practical solutions to curb the menace.
Obesity has become a pressing health issue in recent times. Whether you are obese or not, you can gain a lot by reading this book. You will not only understand what causes obesity, but you will also learn what happens inside your body as you eat or don’t eat different types of food.
Below are the main points I learnt from this book:
Eating less does not reduce obesity
Calories In – Calories Out = Body Fat
This is the most common knowledge circulating for the treatment of obesity. To reduce calories, we need to eat less. According to this theory, if “calories in minus calories out” is positive, there will be weight gain, and if “calories in minus calories out” is negative, there will be weight loss. The biggest flaw in this theory, according to Dr Jason Fung, is that it assumes calories out is independent of calories in. This means that, irrespective of the calories consumed, calories out will remain constant (calories out refers to the energy spent by the body on various metabolic functions, assuming no exercise).
However, in reality, our bodies adapt to the calories consumed. If we reduce calorie intake, the body will not continue to spend the same number of calories as before. It will try to manage its activities within the calorie intake limit. To do so, it will stop some unnecessary functions to conserve energy, thereby reducing the body’s metabolism. This is why there is no long-term weight loss on a low-calorie diet. A low-calorie diet may work initially, but very soon it hits a plateau.
Exercise does not reduce obesity
According to the “calories in, calories out” theory, not exercising is one of the causes of obesity. However, the important point to note here is that calories out, or the total energy expenditure of the body, is not the same as exercise. Total energy expenditure includes multiple factors, such as basal metabolic rate, non-exercise activity, and exercise. Of the total energy expenditure, exercise constitutes only 5%. The remaining 95% is used for basal metabolism. So, doing exercise will not make much of a difference.
Obesity is a hormonal disorder
The author states that obesity is a hormonal disorder rather than a calorific disorder. He explains that two hormones play a crucial role in obesity: insulin and cortisol.
High insulin levels cause obesity. Insulin is a hormone released by the pancreas. Whenever we eat something, our blood sugar rises. In response to rising blood sugar, insulin is secreted to move this sugar to the cells. When we eat frequently, insulin is released continuously. Persistent high levels of insulin lead to insulin resistance. Insulin resistance is the main cause of obesity as well as diabetes.
The second hormone is cortisol, which is released by the adrenal glands. Cortisol causes weight gain by indirectly increasing insulin levels. Cortisol is also known as the stress hormone. Whenever cortisol is released in response to stress, glucose is released into the blood. This was useful in prehistoric times for the fight-or-flight response. When a caveman saw a tiger or a wild animal, the increased glucose in the blood helped him run from danger.
However, the stress in modern times differs from the stress in prehistoric times. Nowadays, we don’t have to run away from threats. There is no immediate life danger, so the glucose released into the blood remains unused. As a natural response to the glucose in the blood, insulin is secreted by the pancreas. Persistent high levels of insulin lead to insulin resistance and obesity.
All calories are not the same
The “calories in, calories out” model of obesity assumes that all calories are the same. However, this is not true. One calorie of sugar (a carbohydrate) is very different from one calorie of olive oil (a fat). Sugar increases blood glucose levels, triggering an insulin response. However, olive oil causes minimal insulin response.
Since insulin, as mentioned earlier, is the root cause of obesity, the sources of our calories matter greatly.
All carbohydrates are not bad
Carbohydrates cause the most weight gain because they are responsible for the greatest increase in insulin levels. However, not all carbohydrates are the same. Sugar and flour are carbohydrates, but so are fruits and vegetables. You are very unlikely to get fat eating vegetables, no matter how much you eat.
The key differentiator here is the processing or refining of carbohydrates. The more processed or refined a carbohydrate is, the stronger the insulin response it generates, leading to increased fat gain. We should choose carbohydrate foods in their natural form. All carbohydrates in their natural form come with a protective factor: fibre. Fibre reduces the insulin-stimulating effect of carbohydrates.
Two step solution to Obesity
Whenever we think about reducing obesity, we focus on what to eat or what not to eat. However, Dr Jason Fung suggests that, to reduce obesity, we need to focus on two things:
What to eat: Dr Fung advises us to completely remove added sugars from our diet, reduce consumption of refined grains, consume moderate protein, natural fats and increase consumption of fiber.
When to eat: In addition to what we eat, the timing of eating also matters significantly. Even eating the right things will not help if meal timings are not corrected. If you eat frequently throughout the day, your insulin levels will remain consistently high. To reduce obesity, you need to lower insulin levels. To reduce obesity, you need to lower insulin levels. To prevent insulin resistance from developing you need to have periods of high insulin levels (eating) followed by periods of low insulin levels (not eating). To achieve this, the author suggests intermittent fasting.
Favourite quote
“Obesity is a hormonal, not a caloric imbalance.”
Click here to buy ‘The Obesity Code‘ on Amazon.