Why do people gain weight?
Our bodies need calories (energy) to keep us alive and active. But to maintain weight we need to balance the energy we take in with the energy we use. When a person eats and drinks more calories than he or she burns, the energy balance tips toward weight gain, overweight, and obesity. The tipping point at which the calories coming in and the calories going out become out of balance and lead to weight gain may differ from one person to another. Your genes, the world around you, and other factors may all affect weight gain.
Other Factors involved
Research shows that obesity tends to run in families, suggesting that genes may contribute to obesity. Families also share diet and lifestyle habits that may affect weight. However, it is possible to manage your weight even if obesity is common in your family.
The World around You
Where people live, play, and work may also strongly affect their weight. Consider the fact that obesity rates were lower 30 years ago. Since that time, our genetic make-up hasn’t changed, but our world has. The world around us affects access to healthy foods and places to walk and be active in many ways:
- Many people drive rather than walk.
- Living in areas without sidewalks or safe places to exercise may make it tough to be more active.
- Many people eat out or get takeout instead of cooking, which may lead to eating more calories.
- Most vending machines do not offer lowcalorie, low-fat snacks.
Overweight and obesity affect people in all income ranges. But people who live in low-income areas may face even greater barriers to eating healthy foods and being active than other people. Highcalorie processed foods often cost less than healthier options, such as fruits and vegetables. There also may be few safe, free, or low-cost places nearby to be active on a regular basis. These factors may contribute to weight gain.
A person’s culture may also affect weight:
- Some cultures have foods with a lot of fat or sugar, making it hard to manage weight.
- Family events at which people eat large amounts of food may make it tough to control portions.
Research suggests that lack of sleep is linked to overweight and obesity. Recent studies have found that sleeping less may make it harder to lose weight. In these studies, adults who were trying to lose weight and who slept less ate more calories and snacked more.
Certain drugs may cause weight gain. Steroids and some drugs to treat depression or other mental health problems may make you burn calories more slowly or feel hungry. Be sure your health care provider knows all the medicines you are taking (including over-the-counter drugs and dietary supplements). He or she may suggest another medicine that has less effect on weight.