Keeping a healthy weight is crucial. If you are underweight or overweight, or have obesity, you may have a higher risk of certain health problems.
About two thirds of adults in the U.S. are overweight or have obesity. Achieving a healthy weight can help you control your cholesterol, blood pressure and blood sugar. It might also help you prevent weight-related diseases, such as heart disease, diabetes, arthritis and some cancers.
Eating too much or not being physically active enough will make you overweight. To maintain your weight, the calories you eat must equal the energy you burn. To lose weight, you must use more calories than you eat. A weight-control strategy might include
Choosing low-fat, low-calorie foods
Eating smaller portions
Drinking water instead of sugary drinks
Being physically active
Eating extra calories within a well-balanced diet can help to add weight.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases