How much a person weighs depends in large part on four things:
- Calories taken in each day.
- Calories burned off each day.
- Age.
- Genetics.
People who regularly eat and drink more calories than they burn each day are more likely to gain extra weight, including belly fat.
Getting older also makes a difference. People lose muscle as they age. And the problem is worse for those who are not physically active. Loss of muscle mass decreases how quickly the body uses calories. That can make it more challenging to maintain a healthy weight.
Many women notice an increase in belly fat as they get older even if they don't gain weight. This is likely due to a lower level of estrogen because estrogen seems to have an effect on where fat is located in the body.
Genes can contribute to an individual's chances of being overweight or obese too. It also plays a role in where the body stores fat.