Why Some People Eat What They Want Without Gaining Weight: Experts Explain

Many people observe friends or family members who seem to eat freely, pizzas, ice cream, donuts, without apparent weight gain, while others meticulously count calories. Experts clarify that this phenomenon isn't due to a secret trick or a drastically faster metabolism present from birth.

“

There is little evidence that some people are born with drastically faster calorie burning without exercise and physical activity.

Instead, weight management is a complex interplay of genetics, dietary habits, behavior, physical activity, and the body's internal regulation of hunger and satiety. Nutrition professor Kathleen Melanson suggests that individuals who appear to eat anything often don't consume more calories than perceived. They might have ice cream one day but unconsciously eat less at another meal or snack less throughout the day. Similarly, someone ordering a pizza might eat slowly, stop when full, and not overindulge like another person might.

Physical activity plays a significant role, not just through organized exercise. Many people naturally move more, walking, fidgeting, having active jobs, or chasing children. This constant, everyday movement expends energy and can influence metabolism, even without gym visits. Experts emphasize that there's scant evidence for a significantly faster calorie-burning rate in some individuals without exercise.

“

People who seem like they can eat anything often don't actually eat more calories than we think.

However, differences in appetite regulation exist. Hormones and nerve signals govern hunger and fullness. In some individuals, this system might be more sensitive. For instance, the hormone leptin helps regulate food intake over time. After a large meal at a party, a person might naturally feel fuller and eat less in the following days, allowing their body to self-correct without conscious calorie counting. Genetics also contribute, with over 250 DNA regions linked to obesity, but genes alone don't dictate weight. A predisposition to gain weight doesn't automatically mean a lack of self-control but rather a complex mix of biology, habits, environment, and lifestyle. Ultimately, the appearance of "eating everything and not gaining weight" is usually a simplified story, masking a combination of factors like consuming fewer total calories, increased movement, or better satiety awareness. Comparing oneself to others is rarely productive, as each body functions uniquely.

“

Genetics also play a role. Researchers have found more than 250 DNA regions associated with obesity, but genes alone do not determine someone's weight.