Doctors and dieticians can recommend a daily calorie intake and make suggestions for healthy meals that include fruits and vegetables, protein-rich foods, and complex high-fiber carbohydrates found in whole grains and brown rice (as opposed to complex carbohydrates found in table sugar and fruit juices).
Patients are also advised to reduce fat intake, control portion sizes, examine food labels for calorie counts, and cut back on junk food.
Over-the-counter meal replacements are another way to reduce calorie intake. While most adults consume 2,000 to 2,500 calories each day, seriously obese patients are sometimes given very low-calorie liquid diets of 800 calories a day.
Specialized diets, often called "fad" diets, vary considerably and range from high-protein, low-carbohydrate diets, to the grapefruit diet, and the cabbage soup diet. Fad diets can help patients lose weight quickly, but most doctors do not endorse them, noting that the results usually are not permanent, and the methods are not healthy.
Fad diets often eliminate important nutrients or cause patients to lose too much weight too quickly. Diets that allow only a very low calorie intake are especially dangerous, as they increase the risk for developing heart murmurs.