Why do we get fat

Chapter 11 The Big Lie of "20 Calories to Help You Lose Weight"
20 calories.

Next time someone tells you that the way to lose weight is to "achieve energy balance and obtain a healthy weight" according to the words of the World Health Organization, please immediately think of this number.Remember that number the next time someone tells you that all you need to do to prevent yourself from slowly gaining weight is to slightly reduce your food calorie intake and increase your physical activity.

Assuming these official claims about weight loss are correct, obesity will be a figment of our collective imagination rather than the most pressing public health problem of our time!
As an official report issued by the USDA states, weight gain is a gradual process.Once you notice that you're gaining weight, learn to moderate your calorie intake while increasing your physical activity, as logically dictates from the theory of calorie balance and weight loss, and things should be fine again.You can skip fast food here and snack there; you can walk longer, spend more time at the gym, and do what you need to do.Even before you make up your mind to lose weight, you know what is necessary to "lose weight right".

If the goal of weight loss is as simple as eating less, taking in fewer calories, exercising more, and burning more calories, then why are these measures ineffective?Why is obesity still so ubiquitous?Why do successful cases of weight loss seem so rare?

That's where the 20 calories in the title come from.

我们来简单计算一下。0.5千克脂肪含有相当于3500卡路里的能量。这就是为什么营养学家告诉我们，要是你想一周减0.5千克体重，你就需要一天减少平均500卡路里摄入的原因——500卡路里乘上7天就相当于一周3500卡路里。

Now let's look at the math in terms of weight gain rather than weight loss.How many extra calories do we need to eat every day to add 1 kilogram of fat every year, and then accumulate more than 25 kilograms of fat for 20 years?How many calories do we need to absorb, not burn, and store in fat tissue all the time, to make us go from a lean body at 25 to a fat, bloated body at 50, as most people do?
The answer is this "magic" number, 20 calories a day.

20 calories a day multiplied by 365 days a year, the annual fat storage is about a little more than 7000 calories, which is about a little more than 1 kilogram of fat.

If obesity is really determined by the balance of calorie intake, the logic behind this implies that you only need to eat an average of 20 calories more per day, and you will gain 20 kg of excess fat in 20 years.On the contrary, it can be concluded that you only need to control yourself to eat less than 20 calories a day, and you can definitely solve the problem of obesity.

How much is 20 calories?That's less calories than a bite of a McDonald's burger or croissant, likewise less than 60ml of Coke or regular beer, less than three bites of potato chips, and probably about the same as three bites of an apple.In short, very little.

20 calories, less than 1% of the daily calorie intake recommended by the National Academy of Sciences for middle-aged housewives, and less than 0.5% of the recommended daily calorie intake for sedentary middle-aged men.Only 20 calories a day, how small it is for the method of losing weight by restoring the balance of calorie intake.

If, as the National Institutes of Health say, in order to maintain weight, we must ensure a balance between the energy we take in and the energy we expend 20 calories will eventually make you fat.

Ask yourself, if all the people who started to gain weight were eating 20 calories more than their energy balance point every day, how could anyone stay lean for life?Yet quite a few people do spend their entire lives being perfectly skinny.In fact, there are also obese people who have successfully maintained their original weight for decades.They are fat all the time, maintaining a balance of calories in and calories out.Obviously, since they weren't getting fatter, they must be doing better than trying to limit themselves to 20 calories a day.How did they do it?

Eating a few extra bites or eating too much (100 to 200 calories above our daily life activity value) can make us lose weight.

If the difference between not eating too much and eating too much (20 calories) is less than 1% of the total calories we absorb in a day, who can control eating with such precision?Simply put, the question we are asking now is not why some of us are fat and why some are not, but how any of us can avoid our fate of becoming fat.

Losing weight became a matter of arithmetic. In 1936, Professor Eugene Du Bois of Cornell University made such an estimate.He told us that if a 75-kilogram man wants to maintain his weight for 20 years—that is, he cannot gain more than 20 kg over 1 years—then he needs to balance his daily calorie intake with his calorie expenditure. The difference is maintained within 1%.Du Bois wrote: "Such precision is difficult even for mechanical devices." Machines can't do it, let alone people?
"We don't yet know exactly why some people get fat," Du Bois added, "and we don't know why some people don't get fat in a society that's overnourished." It's so difficult, he added: "There is nothing more bizarre than maintaining weight in such a complex and variable environment of physical activity and food consumption."

Doesn't the fact that many people stay lean for decades, and that many obese people stay fat (without continuing to gain weight) just suggest that there must be a more convincing explanation for weight control than mere calorie balance theory? ?
Let's consider several new possibilities.It's easy to think now: "Oops! The belt is too tight and you're fat again! You better eat less..." But animals obviously don't think that way, and they still eat when they should.Don't tell me the theory of calorie balance weight loss doesn't work on animals.Some species remain lean and beautiful as adults (momentarily digressing, although some animals, such as walruses and hippopotamuses, don't, and they eat and get fatter), and they don't need to work hard to stay in shape.How do you think they do it?
You might say that the only way to stay in shape is to stay hungry—if not extremely hungry, then at least somewhat hungry.If we can always have something left on our plate and be half full, then we can be assured that we are eating less and reducing our calorie intake.It's better to eat a few hundred calories less than we want than to eat 20 calories more than we need.So, if you want to be thin, you either live in a world where food supplies are scarce, or you eat consciously and in moderation.That means leaving the table before your appetite is satisfied.Or for herbivores, either ensure that they run fast enough not to be killed by predators, or keep fit and eat less grass.

But if eating in moderation means that we consciously eat less, and less...then why this skinny appearance that makes us so gaunt?The calorie balance algorithm doesn't distinguish between weight loss and weight gain, it just states that calories in and calories out must match.If people simply don't have enough food to eat more (average 20 calories per day), then in this case, why is there still so much obese population among these people? —Of course these people exist, and as we have said before, their children are emaciated, stunted, and have the typical symptoms of chronic undernutrition due to food shortages, but there are still a large number of obese adults among these adults.

There must be other factors that determine whether we are fat or thin than just consciously or unconsciously matching the balance of calories in and calories out.In this book, we're going to uncover the real causes of obesity and weight loss failures.To this end, the first questions to be clarified are: where to gain weight, when to gain weight, and why some people and animals do not gain weight no matter what they eat.

(End of this chapter)