Weight gain occurs when a person consumes more calories than their body uses for energy. This excess energy is stored as fat, leading to an increase in body weight. Factors contributing to weight gain can include a sedentary lifestyle, poor dietary choices, and certain medical conditions. Maintaining a healthy weight is important for overall well-being. Nutrition plays a key role, as balanced meals can help manage calorie intake. Regular physical activity, such as exercise, also helps burn calories and can prevent unwanted weight gain. Understanding these factors can aid in making healthier lifestyle choices.