{"id":73793,"date":"2022-07-24T13:31:00","date_gmt":"2022-07-24T17:31:00","guid":{"rendered":"https:\/\/www.shortform.com\/blog\/?p=73793"},"modified":"2026-05-04T16:00:40","modified_gmt":"2026-05-04T20:00:40","slug":"myths-about-obesity","status":"publish","type":"post","link":"https:\/\/www.shortform.com\/blog\/myths-about-obesity\/","title":{"rendered":"5 Myths About Obesity: Debunked by Science"},"content":{"rendered":"\n

What is the main cause of obesity<\/a>? Is obesity a disease or simply a result of eating an excess amount of calories?<\/p>\n\n\n\n

According to Jason Fung, the \u201ccalories in, calories out\u201d theory fails to capture the full picture of obesity. Excess calories play a part, but they aren\u2019t the root cause of obesity. More specifically, this theory fails to appreciate that obesity is a hormonal disease, rather than a problem of willpower or bad eating habits. In his book Obesity Code<\/em>, Fung lays out five mistaken premises that hamper the current model of obesity.<\/p>\n\n\n\n

Here are five myths about obesity debunked. <\/p>\n\n\n\n\n\n\n\n

#1: \u201cAll Calories Are the Same\u201d<\/h2>\n\n\n\n

Traditionally, experts have reduced all foods to calories, or units of food energy, and treated calories as the most important aspect of any food. However, Fung asserts that not all calories are the same. For instance, 100 calories of high-fructose corn syrup is quite different from 100 calories of salmon. Research supports this view, showing that different foods cause different metabolic and hormonal reactions in the body. Because obesity is a hormonal disease, this means that various foods have different impacts on obesity.<\/p>\n\n\n\n

(Shortform note: In Salt Sugar Fat<\/em><\/a>, Michael Moss says that the form<\/em> a calorie comes in is what matters. Specifically, nutritionists have found that we can consume more liquid calories than solid calories before we feel full. This, Moss argues, is a key reason soda companies such as Coca-Cola became so successful\u2014because consumers could drink multiple cans without much thought.)<\/p>\n\n\n\n

#2: \u201cCalories In and Calories Out Function Independently\u201d<\/h2>\n\n\n\n

As Fung explains, these variables in fact depend on each other. Your metabolism adapts to your caloric intake: When you eat less, your metabolism slows down to conserve energy. When you eat more, it temporarily speeds up, having more energy to burn. In other words, you can\u2019t reduce calories in without slowing calories out, and you can\u2019t increase calories out without increasing calories in. So \u201ceat less, move more\u201d can\u2019t<\/em> work, because you need to eat more in order to move more, and vice versa.<\/p>\n\n\n\n

(Shortform note: Gary Taubes makes a similar point in Why We Get Fat<\/em><\/a>: If you want to work up an appetite for, say, a Thanksgiving feast, you\u2019d eat less to save room in your stomach, and you might engage in strenuous exercise to get hungrier. Yet these are exactly the instructions we\u2019re given for weight loss\u2014eat less, exercise more. Isn\u2019t it strange, he says, that our prevailing theory of weight loss is exactly what we\u2019d do to get hungrier?)    <\/p>\n\n\n\n

#3: \u201cExercise Contributes to Weight Loss\u201d<\/h2>\n\n\n\n

The notion that exercise leads to weight loss is a core tenet of the prevailing theory\u2014it\u2019s the \u201ccalories out\u201d part. However, Fung asserts that we\u2019ve misunderstood how the body uses energy<\/strong>: Exercise accounts for a percentage of total energy expenditure, but most energy goes to our \u201cbasal metabolic rate,\u201d which includes beating our hearts and powering our brains.<\/p>\n\n\n\n

Considering these other activities, exercise accounts for only around 5% of energy expenditure, so it\u2019s too small to make a meaningful impact on weight loss. In addition, studies show that: <\/p>\n\n\n\n