TULSA, Okla. –
A new analysis indicates that physical activity alone is not a strong enough factor to prevent weight gain, challenging a long-held assumption about combating obesity.
Researchers found that people burn roughly the same number of calories per day regardless of how active they are. That means someone with a highly physical job and someone working a sedentary office role may end up with similar total daily energy expenditure.
More than 40% of U.S. adults are considered overweight or obese, according to national health data. Obesity is now associated with higher risks for conditions including diabetes, heart disease, neurodegenerative disorders and certain cancers.
The analysis showed that daily calories burned remained relatively stable across different activity levels. Based on the findings, researchers concluded that diet plays a far greater role in weight changes than physical activity.
The research team reported that calorie intake appears to influence body weight at a much higher rate than changes in activity. Scientists also noted that humans tend to consume more food when it is readily available. They identified 14 genetic variants that may increase the likelihood of developing obesity, though lifestyle habits remain a significant factor.
How to manage or reduce weight
Health experts generally recommend maintaining weight by balancing calorie intake with the number of calories the body burns each day, a figure influenced by age, sex and body type. Tools such as the National Institutes of Health’s online calculator can help estimate daily calorie needs.
For weight loss, researchers have found that reducing daily intake by about 500 calories typically results in losing roughly one pound per week.
Why exercise still matters
While exercise may not be the primary factor in preventing weight gain, health experts emphasize that regular activity offers substantial health benefits. Consistent movement supports heart function, mental well-being and long-term physical health.
The study concludes that combining balanced eating habits with steady physical activity remains the most effective long-term strategy for overall health.