Determine your patient’s previous patterns of weight gain and loss. Does he have a family history of obesity, thyroid disease, or diabetes mellitus? Assess his eating and activity patterns. Has his appetite increased? Does he exercise regularly or at all? Next, ask about associated symptoms. Has he experienced visual disturbances, hoarseness, paresthesia, or increased urination and thirst? Has he become impotent? If the patient is female, has she had menstrual irregularities or experienced weight gain during menstruation?

Form an impression of the patient’s mental status. Is he anxious or depressed? Does he respond slowly? Is his memory poor? What medications is he using?

During your physical examination, measure skin-fold thickness to estimate fat reserves. (See Evaluating nutritional status, pages 712 and 713.) Note fat distribution, the presence of localized or generalized edema, and overall nutritional status. Examine the patient for other abnormalities, such as abnormal body hair distribution or hair loss and dry skin. Take and record the patient’s vital signs.

Evaluate the patient’s weight distribution by measuring his waist circumference around his abdomen at the level of the iliac crest. If the measurement is greater than 35″ (89 cm) for a woman or 40″ (102 cm) for a man (with a normal body mass index), the patient is at greater risk for health problems. People with a high distribution of fat around their waists, as opposed to their hips and thighs, are at greater risk for such diseases as type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease.

♦ Acromegaly. This disorder causes moderate weight gain. Other findings include coarsened facial features, prognathism, enlarged hands and feet, increased sweating, oily skin, deep
voice, back and joint pain, lethargy, sleepiness, heat intolerance and, occasionally, hirsutism.

♦ Cushing’s syndrome (hypercortisolism). Excessive weight gain, usually over the trunk and the back of the neck (buffalo hump), characteristically occurs in this disorder. Other cushingoid features include slender extremities, moon face, weakness, purple striae, emotional lability, and increased susceptibility to infection. Gynecomastia may occur in men; hirsutism, acne, and menstrual irregularities may occur in women.

♦ Diabetes mellitus. The increased appetite associated with this disorder may lead to weight gain, although weight loss sometimes occurs instead. Other findings include fatigue, polydipsia, polyuria, nocturia, weakness, polyphagia, and somnolence.

♦ Heart failure. Despite anorexia, weight gain may result from edema. Other typical findings include paroxysmal nocturnal dyspnea, orthopnea, and fatigue.

♦ Hyperinsulinism. This disorder increases appetite, leading to weight gain. Emotional lability, indigestion, weakness, diaphoresis, tachycardia, visual disturbances, and syncope also occur.

♦ Hypogonadism. Weight gain is common in this disorder. Prepubertal hypogonadism causes eunuchoid body proportions with relatively sparse facial and body hair and a high-pitched voice. Postpubertal hypogonadism causes loss of libido, impotence, and infertility.

♦ Hypothalamic dysfunction. Conditions such as Laurence-Moon-Biedl syndrome cause a voracious appetite and subsequent weight gain along with altered body temperature and sleep rhythms.

♦ Hypothyroidism. In this disorder, weight gain occurs despite anorexia. Related signs and symptoms include fatigue; cold intolerance; constipation; menorrhagia; slowed intellectual and motor activity; dry, pale, cool skin; dry, sparse hair; and thick, brittle nails. Myalgia, hoarseness, hypoactive deep tendon reflexes, bradycardia, and abdominal distention may occur. Eventually, the face assumes a dull expression with periorbital edema.

♦ Metabolic syndrome. This syndrome, previously called syndrome X, consists of a group of disorders that affect metabolism, including excessive weight gain (usually in the central abdomen), hypertension (blood pressure greater than 135/85 mm Hg), abnormal cholesterol levels (high low-density lipoprotein and triglyceride levels, low high-density lipoprotein level), and high insulin levels. Inefficient use of insulin in the body is thought to be a major contributor to metabolic syndrome, as are physical inactivity, poor diet, and genetic factors. Individuals with metabolic syndrome are at a significantly increased risk for heart disease, stroke, and diabetes. Treatment typically involves exercising, following a hearthealthy diet, and refraining from smoking; medical therapy may be prescribed to treat the individual disorders.

♦ Nephrotic syndrome. In this syndrome, weight gain results from edema. Severe edema (anasarca) can increase body weight by up to 50%. Related effects include abdominal distention, orthostatic hypotension, and lethargy.

♦ Pancreatic islet cell tumor. This type of tumor causes excessive hunger, which leads to weight gain. Other findings include emotional lability, weakness, malaise, fatigue, restlessness, diaphoresis, palpitations, tachycardia, visual disturbances, and syncope.

♦ Preeclampsia. In this disorder, rapid weight gain (exceeding the normal weight gain of pregnancy) may accompany nausea and vomiting, epigastric pain, elevated blood pressure, and blurred or double vision.

♦ Sheehan’s syndrome. Most common in women who experience severe obstetric hemorrhage, this syndrome may cause weight gain caused by impaired pituitary gland function.

♦ Drugs. Corticosteroids, phenothiazines, and tricyclic antidepressants cause weight gain from fluid retention and increased appetite. Other drugs that can lead to weight gain include hormonal contraceptives, which cause fluid retention; cyproheptadine, which increases appetite; and lithium, which can induce hypothyroidism.

Psychological counseling may be needed for patients with excessive weight gain, particularly when it’s caused by emotional problems or alters body image. If the patient is obese or has a cardiopulmonary disorder, any exercise should be monitored closely. Further study to rule out possible secondary causes should include thyroid-stimulating hormone determination and dexamethasone suppression testing. Laboratory test results of all patients ideally include cardiac risk factors: cholesterol, triglyceride, and glucose levels.

Weight gain in children can result from an endocrine disorder such as Cushing’s syndrome or from disorders that cause inactivity, such as Prader-Willi syndrome, Down syndrome, Werdnig-Hoffmann disease, late stages of muscular dystrophy, and severe cerebral palsy.

The incidence of obesity is increasing among children. Nonpathologic causes include poor eating habits, sedentary recreation, and emotional problems, especially among adolescents. Regardless of the cause, discourage fad diets and provide a balanced weight loss program.

Desired weights (associated with lowest mortality rates) increase with age.

Educating the patient about weight control is extremely important. Stress the benefits of behavior modification and dietary compliance. Help the patient plan an appropriate exercise routine.

Begin with a thorough diet history because weight loss is almost always caused by inadequate caloric intake. If the patient hasn’t been eating properly, try to determine why. Ask about his previous weight and whether the recent loss was intentional. Be alert for lifestyle or occupational changes that may be causing anxiety or depression. For example, has he gotten
separated or divorced? Has he recently changed jobs?

Inquire about recent changes in bowel habits, such as diarrhea or bulky, floating stools. Has the patient had nausea, vomiting, or abdominal pain, which may indicate a GI disorder? Has he had excessive thirst, excessive urination, or heat intolerance, which may signal an endocrine disorder? Take a careful drug history, noting especially the use of diet pills or laxatives.