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Why Losing Weight Can Be Bad for Your Health

It might be better to remain steadily overweight than lose and regain pounds.

Key points

  • About 80 percent of people who lose a significant amount of body weight will regain it, sometimes with interest.
  • People tend to gain weight in fat rather than muscle, which makes the pounds harder to lose in the future.
  • Following professional advice and finding ways to take accountability can help individuals lose the weight—and keep it off.

Given America’s shocking obesity epidemic—that has been made much worse by the COVID-19 pandemic—it’s no surprise that many people want to lose weight, and many doctors encourage their patients to do so. Indeed, it is an irrefutable fact that when overweight people drop pounds, they usually enjoy better medical health, better mood, and improved quality of life. That’s why the weight loss business is a gigantic, multi-billion-dollar industry, because so many people are desperate, or at least very eager, to lose a significant amount of weight and will pay a pretty penny for the chance of good results.

But there is a serious downside to losing weight that, ironically, results in worse medical health and poorer mental health. This is the overwhelming likelihood that people who lose a significant amount of weight, usually about 10 to 25 percent of their body mass, will almost inevitably regain it. And often more than they lost.

The weight loss struggle

In fact, many studies have concluded (conservatively) that 80 percent of people who lose a significant amount of body weight will regain it within a few years, often much sooner (e.g., Blomain et al., 2013). Because, as many people know, losing weight is hard enough, but keeping it off is much, much harder. In essence, this means that 80 percent of people who lose a significant amount of weight will actually be medically and psychologically worse off in a year or two than if they didn’t lose weight in the first place. Because the more body fat an overweight person has, the greater their risk is for diabetes, high cholesterol, elevated blood pressure, gastrointestinal illness, musculoskeletal problems, sexual dysfunction, and even some cancers. And, of course, it is very dispiriting to regain weight once having gone through the effort to lose it.

For me, this poses an important ethical consideration: Unless someone is morbidly obese, is it better to help them come to terms with their obesity or help them to safely lose weight? Because unless we are talking about hugely impactful, debilitating, or potentially lethal conditions, a treatment that has an 80 percent failure rate would be far down on the preferred intervention list.

Interestingly, weight loss is actually very simple. If a person expends more calories than they consume, their weight will decrease. If a person consumes more calories than they expend, their weight will increase. And if the amount of calories consumed is essentially equivalent to the amount expended, their weight remains stable. Thus losing weight is a simple matter of the physics of energy balance. But as theoretically simple as it is, losing weight and keeping it off is not easy. Hence the very high failure rate.

To make matters worse, weight cycling, or “yo-yo-ing,“ can be very unhealthy because when weight goes down and up repeatedly, people actually become “fatter“ (i.e., their percentage of body fat increases, and their muscle mass decreases) even if their maximum weight never rises above a certain point. Indeed, some studies suggest as much as 25 percent of weight reduction is due to the loss of muscle mass (e.g., Cava et al., 2017). What’s more, since muscle is a calorie-burning furnace while fat maintenance requires very little caloric energy, losing muscle leads to a generally slower metabolism. Meaning people burn fewer calories at rest the less muscle they have, which facilitates weight gain. Alternatively, the more muscle mass a person has, the greater their calorie burn at rest.

Here’s how it works. If a typical 250-pound obese person (obesity is defined as having a body mass index—BMI—of 30 or above) loses 50 pounds, it is almost a certainty that they will lose about 10 pounds of muscle. But when they regain the weight so that they weigh 250 pounds again, it is extremely unlikely they will have regained a single pound of muscle. So after this initial weight-loss/weight-gain cycle, they actually have a higher percentage of body fat than they did initially. And every time this cycle is repeated, the net result is steadily increasing body fat and decreasing muscle mass. This is why unless a person can maintain the lost weight, it is better not to lose it in the first place.

How to shed the pounds—and keep them off

There are ways, however, to land in the happy 20 percent minority of people who do enjoy long-term success and all the benefits that come with it.

1. Follow the advice of a bona fide nutritionist, dietitian, or behavioral health professional. This will ensure that you will maintain good nutrition while reducing calories and losing weight at a healthy pace.

2. Do increasingly challenging and consistent resistance and strength training during the weight loss phase and regular, ongoing exercise thereafter.

3. Keep a food journal religiously! Indeed, research has shown a powerful correlation between assiduously maintaining a food journal and successful, long-term weight reduction. Food journals are good predictors of success for several reasons: (1) heightened awareness of exactly what you're eating; (2) accountability because you'll have a literal record of your choices that can be reviewed by a health specialist; (3) reactivity, which is the phenomenon of something changing simply because it's being measured or observed; (4) motivation because it is a major challenge to diligently write down every meal, scrap, morsel, and crumb you eat and drink. So having the dedication to do it consistently—not for only a few weeks or even months, but over the long haul for several years—reflects one's determination, discipline, and willingness to persevere in the face of challenges and even setbacks.

4. Deemphasize “losing weight,” per se, and instead reframe the effort as “gaining health.” Because when people consistently engage in healthy eating and exercise behaviors, it is almost inevitable they will enjoy the “side-effect“ of losing body fat without sacrificing much muscle mass.

Remember: Think well, act well, feel well, be well!

Copyright 2021 Clifford N. Lazarus, Ph.D. This post is for informational purposes only. It is not intended to be a substitute for professional assistance or personal mental health treatment by a qualified clinician.

Dear Reader: The advertisements contained in this post do not necessarily reflect my opinions nor are they endorsed by me. —Clifford


Blomain, et al (2013). Mechanisms of Weight Regain Following Weight Loss.

Cava, et al (2017). Preserving Healthy Muscle During Weight Loss.