Weight gain

Weight gain is an increase in weight in the body. This can involve an increase in muscle, fat, excess fluids such as water or other factors. Weight gain can be a symptom of a serious medical condition.

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Description

Weight gain occurs when more energy (as calories from food and drink) is gained than the energy expended by life activities, including normal physiological processes and physical exercise.^[1]

If enough weight is gained due to increased body fat deposits, a person may become overweight or obese, generally defined as having more body fat (adipose tissue) than is considered good for health.^[1] The Body Mass Index (BMI) measures body weight in proportion to height, and defines optimal, insufficient, and excessive weight based on the ratio.^[2]