If You Weigh 400 Pounds, How Much Weight Can You Lose in One Month?

Weighing 400 pounds classifies you as obese, according to the National Heart, Lung and Blood Institute. Although weight-loss surgery is often appropriate for obese individuals who have failed using other weight-loss strategies, diet and exercise are cheaper alternatives. The amount of weight a 400-pound person will lose in one month depends on the type of weight-loss strategy he uses.

Very Low-Calorie Diets

Very low-calorie diets are often use for obese individuals with immediate risks for health conditions, such as heart disease and diabetes. VLCDs generally contain 800 -- or fewer -- calories a day. Weight-control Information Network suggests you can lose up to 5 pounds per week, or 20 pounds in one month, using VLCDs. However, due to potential risks associated with very low-calorie diets, such as nutrient deficiencies, nausea, diarrhea and gallstone formation, they are only appropriate when used under medical supervision.

Low-Calorie Diets

Diets containing 1,000 to 1,600 calories a day are often classified as low-calorie diets, or LCDs. While 1,000- to 1,200-calorie weight-loss plans are usually effective for women, 1,200- to 1,600-calorie diets are often effective for most men, Weight-control Information Network suggests. When following a reduced-calorie diet for weight loss, aim to lose 1 to 2 pounds per week – or up to 8 pounds in a month -- suggests the Centers for Disease Control and Prevention. This rate of weight loss is safe for obese individuals, with or without medical supervision.

Weight-Loss Surgery

Although weight-loss surgery comes with risks, individuals who weigh 400 pounds may benefit from undergoing bariatric surgery. After weight-loss surgery, the University of Michigan Adult Bariatric Surgery Program reports the average weight loss is 5 to 15 pounds per week, or 20 to 60 pounds in the first month. However, drawbacks – such as hair loss and nutrient deficiencies -- can occur with such rapid weight loss. The University of Maryland Medical Center notes that mortality occurs in 1 out of every 200 patients who undergo weight-loss surgery. Therefore, talk with your doctor to determine if bariatric surgery is right for you.

Exercise

Adding physical activity to your weight-loss program can enhance weight loss and help keep lost weight off long term. Safe but effective initial workouts for 400-pound individuals include low-impact exercises, such as light resistance training, swimming, water aerobics, walking, biking or using an elliptical machine. Start at a low intensity for short durations, maybe 10 minutes at a time, and work up to exercising 45 to 60 minutes, five to seven days per week, suggest authors of a review published in a 2009 issue of “The Ochsner Journal.” Always obtain your doctor’s permission before beginning a new workout program, especially if you weigh 400 pounds.