Why do we get fat

Chapter 8 Exercise to lose weight, does it really work? (1)
Imagine that you are invited to a celebratory dinner.The chef's cooking skills are superb, and the invitation stated that this special dinner will be a feast of delicacies from mountains and seas.The invitation also said, in order to whet your appetite, please come hungry.what should you do?
You might try to eat less throughout the day—maybe even skip lunch, or neither breakfast nor lunch—maybe you'll hit the gym for vigorous exercise, maybe run longer, swim longer Swim to keep your hunger up.Maybe you even plan to walk to the dinner rather than drive there for the same purpose.

Now, let's think about it for a moment.To lose weight, we are often instructed to eat less (reduce the calories we eat) and move more (increase the calories we burn).But don't these instructions seem to say: our purpose is to maintain hunger, so as to increase appetite to eat more?
We've seen the problems with losing weight by eating less.Now let's examine the other side of the calorie in and calorie out equation.What happens when we increase energy expenditure by increasing our physical activity?
Today, it's widely accepted that being sedentary is as much a contributor to weight problems as we are eating more.Because of the possibility that heart disease, diabetes and cancer are making us fatter, our sedentary nature in life is also seen as a major contributor to these diseases.Regular physical activity is now seen as the mainstay of protection against all the chronic diseases in our lives—except, of course, for joint and muscle problems caused by overactivity.

Considering the overwhelming amount of information about weight loss, and the fact that maintaining weight is very relevant to our lives, and the concept of exercise to lose weight itself is simple and clear - burn calories, lose weight, prevent disease - if it is true, is this a good thing ?As a culture, we are supposed to believe that this is a good thing.The idea that physical activity is good for health is so pervasive that any scientific fact that disputes this health and lifestyle point of view is dismissed as worth mentioning.

Regular physical activity has undeniable benefits.By exercising, we increase our stamina and immunity, and as experts point out, we may live longer due to a reduced risk of heart disease or diabetes (although this has not been rigorously tested).We just feel better about ourselves.Obviously, many people who exercise regularly become very active, including myself.But what I want to discuss here is not whether exercise is fun for us, a good thing, or a necessary adjunct to a healthy lifestyle as the authorities keep suggesting to us, but whether exercise can help us maintain weight when we lose weight. Weight, which helps us lose weight when we gain weight.

Answer: No.

Let's see why.I want to start with the phenomenon I mentioned in Chapter 1 that obesity is linked to poverty.In the United States, Europe and other developed countries, poorer people are more likely to be fatter.Likewise, the poorer we are, the more likely we are to work physically active jobs and use our bodies rather than our brains to support our families.

In developed countries, it is the poor and disadvantaged who do this kind of heavy manual labor, and they live very hard-this is not a symbolic statement, it is the truth.They don't have the money to attend health clubs, and they don't spend their free time (if any) training for their next long run.They were more likely than the wealthy to work as servants and guards on ranches and factories, and to do manual labor in mines and construction sites.The fact that the poorer we are, the more likely we are to be fatter is enough to call into question the assertion that the amount of energy we expend on a daily basis is related to whether we are fat or not.If factory workers and oil field workers are fat, as I said earlier, it is hard to imagine such a large gap in the daily energy consumption of each person.

Another good reason to question this assertion is the obesity epidemic itself.Over the past few decades, we have continued to gain weight.Many authorities, including the World Health Organization, point out to us that we are becoming less and less active.But the evidence suggests otherwise. At least in the United States, the obesity epidemic has fueled an epidemic of what we call "recreational physical activity."These activities range from health clubs to energy-sapping emerging sports recreations such as roller skating, mountain biking, hiking machines, spinning aerobics, Brazilian martial arts classes, and many more.Virtually all of the above forms of activity have been invented or modified since the obesity epidemic.

There are many ways to quantify the prevalence of this type of physical activity.For example, annual revenues for the health club industry ballooned from about $1972 million in 2 to $2005 billion in 160.Even adjusted for inflation, that's a 17-fold increase. In 1964, the first Boston Marathon had more than 300 participants; by 2009, there were already more than 26000 participants of both men and women. In 1970, there were only 137 participants in the first New York Marathon. In 1980, there were 16000 official runners. In 2008, the number reached 39000, and the number of applicants reached 60000.According to the report of Marathon Guide.com, regardless of tens of thousands of half-marathon races, in 2009 the United States arranged about 400 full marathons (about 42 kilometers) and more than 50 ultra-marathons (about 160 kilometers). And 160 additional ultra-marathon (approximately 4988 kilometers) races.

Until the 20s, Americans didn't think they had to spend their leisure time sweating, and if they could, they didn't.By the mid-70s, as William Bennett and Joel Gurin noted in their 70 weight-loss book, The Dieter's Dilemma: "Seeing someone in a colorful The 'lingerie' in my 'underwear' seemed a bit weird when I was running on a city street." But that soon changed.

Indeed, the New York Times reported in 1977 that America was in the midst of a "physical exercise explosion."This happened precisely because the "exercise is not good for health" philosophy that prevailed in the 60s was transformed into "emerging conventional wisdom that physical activity is good for health". In 1980, the "Washington Post" reported that about 1 million Americans had become active members of the "new health revolution", many of whom would have been ridiculed as "health lunatics" 10 years ago.In addition, the report also stated: "What we are seeing now is one of the major social events at the end of the 20th century."

But if sitting for long periods of time makes us fat, and exercise prevents it, shouldn't the explosion of physical activity and the rise of the new health revolution should lead to more and more lean bodies?

As it turns out, there is very little evidence that the calories we consume have any effect on weight loss. When the American Heart Association and American College of Sports Medicine published joint guidelines on physical activity and health in August 2007, they were conspicuously dismissive when it came to evidence that such exercise isn't effective for weight loss.Many of these expert authors are strong supporters of the important role exercise plays in a healthy lifestyle.In short, these are the people who really want us to exercise and are trying to cite overwhelming evidence to motivate us to do so.They say 8 minutes of moderate-intensity physical activity five days a week is necessary to maintain and promote health.

But when it comes to how physical activity affects our ability to gain or lose weight, these experts can only be vague: "It is reasonable to assume that groups of people who expend relatively more energy per day will, over time, lose weight compared with those who expend less energy. They are less likely to gain weight. So far, however, the data supporting this hypothesis have not been particularly convincing."

The guidelines from the American Heart Association and American College of Sports Medicine differ from those recently put out by other authorities -- the U.S. Department of Agriculture, the International Society for the Study of Obesity, and the International Obesity Task Force.These institutions all recommend that we should exercise 1 hour a day.But the reason why these authorities advocate more exercise is not to help us lose weight. They imply that we cannot lose weight by exercise alone, but of course, exercise still helps to keep us from getting fatter.

What is the secret behind the authority's suggestion of exercising for an hour a day?Very little research can tell us what happens when people exercise for more than 1 minutes a day.So, these authorities can only imagine, more exercise might make a difference.USDA guidelines recommend 60 minutes of moderate physical activity, or 90 minutes per day.It may be necessary to maintain the weight without regaining weight, but they don't think that more than 90 minutes of exercise will reduce the weight!
In 2000, two Finnish exercise physiologists published a study that is often used as the basis for evaluation in professional guidelines.The two researchers focused on whether successful dieters could keep the weight off.They found that in the experiment, everyone gained weight afterwards.And depending on the type of trial, the exercise factor sometimes decreased the growth rate and sometimes increased it.The Finns concluded, with characteristic conservatism, that the relationship between exercise and weight loss was "more complicated" than they could have imagined.

More telling are the results of a study published in 2006 by Paul Williams, a statistician at Lawrence Berkeley National Laboratory in California, and Peter Wood, a Stanford scholar who studies the effects of exercise on health. (Peter Wood).Williams and Wood collected detailed information on about 13000 subscribers of Running World magazine and compared the number of miles they ran each week with their yearly weight change.At first, those who ran the most seemed to weigh the least.But all long-distance runners get fatter over time, even those who run about 64 kilometers a week.

These findings led Williams and Wood, two believers in the theory that "caloric intake balance is closely related to weight loss," to suggest that long-distance runners need to increase their weekly long-distance running mileage every year if they want to maintain weight without regaining weight.According to Williams and Wood's recommendations, the weekly long-distance running mileage that men need to increase is 3 kilometers per year, and that of women is 4.8 kilometers-so that they can maintain their weight and not gain weight.Because they believe that long-distance running must consume those fated calories, otherwise these calories will accumulate in the form of fat and make us fat.

Let's look at the logic behind it.Imagine a man in his 20s who runs 30 kilometers a week, about 5 days a week, 6 kilometers a day.According to the recommendations of Williams and Wood and the logic of the theory that calorie intake is related to weight loss, then by the age of 30, the long-distance running distance of this man must double to become 5 kilometers a day, 12 days a week; Sometimes it is doubled to 40 days a week, 5 kilometers a day-this can prevent the accumulation of fat and maintain a fit body.And if a woman in her 18s runs 20 kilometers a day, 5 days a week, when she is in her 5s, her daily long-distance running distance must increase to 40 kilometers in order to keep her slim.If, on average, she runs 15 kilometer in 5 minutes (this is a good pace for long-distance running), then she'd better be prepared to spend an hour or two on long-distance running every day in order to maintain her weight. In order not to gain weight.

If we believe in the inextricable relationship between calorie balance and weight loss, and thus conclude that we must run a half marathon five days a week (you need to run more in your 40s than in your youth, 50 Running more in our teens, and more in our 60s...) to maintain our weight—well, it might be time again to question the fundamentals of weight loss.Perhaps there are other factors that determine whether we gain weight more than calories in and out.

The widespread belief in the belief that the more calories we burn, the less we weigh is ultimately based on observations in reality and assumptions provided by expert research.The phenomenon is that thin people tend to exercise more than those who are obese - there is no doubt about it.Generally, marathon runners are not overweight, and the leaders in a marathon usually look emaciated.

But it doesn't tell us whether these runners will gain weight once they stop running, or whether obese men and women will become slim marathon runners if they maintain long-distance running as a long-term habit?
Our belief that exercise burns fat is based on the assumption that we can increase energy expenditure (exercise) without increasing energy intake (food).According to New York Times reporter Gina Kolata's calculations in her 2004 book "Ultimate Health," if we burn an extra 150 calories a day through exercise for a month, at the same time, " No increase or change in your diet", then you can lose 0.5 kg.

Having said that, the key question is: Is there a reasonable possibility of this approach?We can increase calorie expenditure and burn an extra 150 calories per day (say, from sitting still to being active, or from being active to being active) without changing our diet, never eating more— - Is this really possible?
The answer is simple - again - how is this possible? !If we increase our physical activity, our appetite will be awakened.If you're out for a walk, cleaning, going on a long hike, playing a few rounds of tennis or 18 holes of golf, you're sure to whet your appetite.You'll feel hungry and get hungrier.If you increase the energy expended, you compensate by increasing the energy intake.

We tend to forget the basic principles that are widely known in life, but also in kinesiology and nutrition: awaken the instinct of appetite, and the basic common sense that the human body needs to increase energy intake to compensate for its increased consumption.This kind of forgetting is simply a bizarre story in the history of modern medical research.

As early as 1932, Mayo Clinic obesity and diabetes specialist Russel Wilder noted in a lecture on obesity that his obese patients lost more weight during bed rest, " Unusually high-intensity physical activity slows weight loss."Wilder believes: "The obese person himself thinks that the more he exercises, the more fat he should burn, and the weight should be lost in proportion. So when he sees no progress in the weight displayed on the scale, he will Get discouraged faster."

As Wilder and his contemporaries pointed out, the reasoning of obese people has two shortcomings: first, when we exercise moderately, we burn significantly fewer calories, at least not as many as we think; The effect achieved by exercise is easy to break, and unconscious adjustments to diet may cause the weight loss effect to weaken. In 1942, Louis Newburgh (Louis Newburgh) of the University of Michigan estimated that a man of about 113 kg could consume 3 calories by climbing one flight of stairs, "he would have to climb 20 flights of stairs to consume a mere piece of bread." contained calories".

(End of this chapter)