By Harshit
WASHINGTON, DECEMBER 20 —
Americans are deeply preoccupied with dieting, body size, and weight loss — an obsession fueled by alarming obesity statistics and a massive commercial industry built around shrinking bodies. Today, 40.3% of U.S. adults live with obesity, according to the US Centers for Disease Control and Prevention, while the global weight-loss and diet market is projected to nearly double from $143 billion in 2022 to about $299 billion by 2030.
Add to that the explosive rise of GLP-1 drugs — originally developed to treat type 2 diabetes and now used by more than 15 million Americans for weight loss — and it’s clear why the scale has become the centerpiece of health conversations.
But a growing body of medical research suggests this focus is misplaced.
Health experts increasingly argue that fitness, strength, and cardiovascular capacity matter far more for long-term health and longevity than body weight or appearance.
Why Weight Loss Isn’t the Same as Health
“We know so many ways to make people healthier other than weight loss,” said Dr. Lisa Erlanger, clinical professor of family medicine at the University of Washington and president of the Association for Weight and Size Inclusive Medicine.
“Just increasing your steps or increasing your muscle strength, when done long-term, can reduce your chances of cancer, depression and diabetes — in addition to lowering the risk of cardiovascular disease and all-cause mortality,” Erlanger said.
A 2024 meta-analysis supports this view, concluding that improving cardiorespiratory fitness delivers lasting health benefits — while weight loss achieved through dieting is rarely sustained long enough to provide long-term protection.
In fact, researchers found that most people regain lost weight, which means any short-term metabolic improvements often disappear.
Obesity Is More Complex Than Calories In vs. Calories Out
Scientists still cannot fully explain why obesity rates began rising sharply around 1980, said Dr. Glenn Gaesser, professor of exercise physiology at Arizona State University and co-author of the 2024 analysis.
While factors such as larger portion sizes, excess sugar, reduced physical activity, and ultra-processed foods play roles, Gaesser emphasizes that the causes go far deeper.
“Our environment has changed with regards to our exposure to chemicals, like plastics, pesticides and herbicides,” Gaesser said. “Many of these ‘forever chemicals’ affect the endocrine system and can disrupt energy balance.”
These substances — known as PFAS (per- and polyfluoroalkyl substances) — persist in the environment and the human body, potentially influencing metabolism.
Researchers have also linked certain viral infections, such as human adenovirus-36, with increased obesity risk — underscoring that body weight is influenced by biology, not just behavior.
“Obesity is not just the difference between energy in and energy out,” Gaesser said.
Why Dieting Fails — and Often Backfires
Dieting, experts say, is one of the least effective ways to improve long-term health.
“One thing that raises body sizes without a doubt are attempts to lose weight,” Erlanger said.
Studies estimate that more than 80% of people who lose significant weight regain it within five years. This happens because the body has a genetically influenced weight range and is biologically programmed to defend against perceived starvation.
When calories are restricted:
- Metabolism slows
- Hunger hormones surge
- Sleep quality worsens
- Cravings intensify
“All of the things we blame fat people for — being lazy, preferring junk food — that is what their body is telling them to do,” Erlanger explained. “Their body is just trying to survive.”
Repeated cycles of weight loss and regain — known as weight cycling or yo-yo dieting — are linked to higher risks of cardiovascular disease, diabetes, bone fractures, vascular dysfunction, and certain cancers, according to Gaesser.
Fitness Protects Health — Regardless of Size
The most consistent predictor of longevity is not thinness, but physical fitness.
People with higher levels of movement, strength, and endurance experience:
- Lower cardiovascular risk
- Reduced cancer rates
- Better mental health
- Lower all-cause mortality
— even when body weight remains unchanged.
“The research is definitive,” Erlanger said. “If you want to improve your health, you shouldn’t diet — you should go for a walk.”
That movement doesn’t need to be extreme or punishing. Experts recommend activities that are enjoyable and sustainable, such as:
- Walking
- Cycling
- Dancing
- Gardening
- Hiking
(Always consult a physician before starting a new activity, and stop if pain occurs.)
Rethinking Health in America
America’s fixation on thinness often overshadows what truly matters: function, strength, stamina, and well-being.
The evidence increasingly shows that you can be healthy, resilient, and long-lived without achieving a culturally ideal body size — and that chasing weight loss at all costs may do more harm than good.
As Erlanger put it bluntly:
“More people want to be smaller, not healthier.”