Weight loss: Why your brain is programmed to keep you fat.

(Dan Tri Newspaper) - For decades, we've generally understood weight loss to be a matter of willpower: eat less, exercise more, but modern science has proven this to be actually incorrect.

Losing weight and maintaining a fit physique has always been a major challenge for many people. Modern science is gradually revealing the mysteries behind this phenomenon, showing that the human body is "programmed" to resist weight loss, a biological mechanism originating from our distant ancestors.

When you lose weight, your body reacts as if it's a threat to survival (photo: pexels/pavel danilyuk, CC BY).

Ancestral heritage

Hundreds of thousands of years ago, body fat was vital for our human ancestors. Too little fat meant starvation, while too much could slow movement.

Over time, the human body has developed complex biological defense mechanisms, connected to the brain, to protect its energy reserves. These systems have helped us survive times of food scarcity.

However, in the modern world , where food is abundant and travel is optional, these very mechanisms become major obstacles to weight loss.

When a person loses weight, the body reacts as if facing an existential threat. Hunger hormones surge, appetite increases, and energy expenditure decreases.

These adaptations evolved to optimize energy storage and utilization in environments with unstable food sources. But today, with easy access to cheap, high-calorie junk food and sedentary lifestyles, these adaptations are causing numerous problems.

Recent research has shown that our brains have powerful mechanisms to protect body weight and can "remember" past weights. For our ancestors, this meant that if they lost weight during difficult times, their bodies would be able to "return" to normal weight at more favorable times.

But for modern humans, this means our brains and bodies remember any excessive weight gain as if survival depended on it. Once the body is heavier, the brain will consider that extra weight as the new normal, a level it feels compelled to protect.

This ability to "remember" weight explains why so many people regain weight after dieting. This isn't due to a lack of discipline, but rather because our biology is doing exactly what it evolved to do: resisting weight loss.

Cracking Biology: Hope from Medicine and Science

Weight-loss drugs offer new hope. They work by mimicking gut hormones, which instruct the brain to suppress appetite.

However, not everyone responds well to these medications, and side effects can make maintenance difficult. Once treatment is stopped, the biological clock usually recovers, and the weight loss will return.

Your body and brain have a way of remembering your heaviest weight and constantly trying to get you back there (photo: pexels/julia larson).

Advances in obesity and metabolism research could open the door to future therapies that minimize the signals that cause the body to revert to its original weight, even after treatment is complete.

The research also indicates that good health doesn't equate to "ideal weight." Exercise, sufficient sleep, a balanced diet, and mental health can all improve cardiovascular and metabolic health, even when weight remains virtually unchanged.

Obesity is not just an individual problem; it requires a whole-society approach to address its root causes. Preventive measures that can make a difference include investing in healthier meals in schools, reducing the marketing of junk food to children, designing neighborhoods that prioritize walking and cycling, and restaurants with standardized portion sizes.

Scientists are also paying particular attention to the critical early stages of life, from pregnancy to about seven years of age, when a child's weight regulation system is especially volatile.

Research has found that parents' diets, infant feeding practices, and childhood lifestyle habits can all shape how the brain controls appetite and fat storage for years to come.

Advice for those who want to lose weight

If you're looking to lose weight, focus on reducing extreme dieting and instead concentrate on sustainable habits that support overall health.

For example, prioritizing sleep helps regulate appetite, while regular activity, even walking, can improve blood sugar levels and cardiovascular health.

The key point is that obesity is not a personal failure, but a biological condition shaped by our brains, genes, and environment.

Advances in neuroscience and pharmacology are opening up new treatment opportunities, while preventative strategies could be game-changers for future generations.

So if you're struggling to lose weight and maintain it, know that you're not alone and it's not your fault. The brain is a formidable opponent. But with science, medicine, and smarter policies, we're beginning to "change the rules of the game."

Source: https://dantri.com.vn/khoa-hoc/giam-can-ly-do-nao-duoc-lap-trinh-de-giu-cho-ban-beo-20251209024115418.htm