Unintentional weight gain is an increase in body weight that occurs when a person takes in more calories than the body needs or uses.

Almost 40% of all Americans are overweight. As we age, our metabolism slows, which can cause weight gain unless we also reduce the amount of food we eat and get adequate exercise.

Weight gain can also be a significant symptom of several endocrine diseases such as Cushing syndrome or hypothyroidism. It may also indicate a heart or lung disorder.

A continued weight gain occurs with pregnancy, whereas a periodic weight gain may occur with menstruation. A rapid weight gain may be a sign of dangerous fluid retention.

• Alcohol use
• Certain drugs such as corticosteroids, cyproheptadine, lithium, tranquilizers, phenothiazines, some antidepressants, and medicines that increase fluid retention and cause edema
• Cushing syndrome
• Eating too much and exercising too little
• Emotional factors such as guilt, depression, and anxiety
• High-carbohydrate, high-calorie diet
• Hypothyroidism
• Polycystic ovary syndrome
• Slower metabolism, which is normal with aging
• Quitting smoking