The Fastest Diet To Lose Weight

Want to lose 20 pounds--or more--in seven days? All you have to do is skip eating, exercise for eight hours a day, take laxatives--and pray you don't end up in the hospital or grave before you reach your goal. Extremely rapid weight loss is possible, but not advisable. And just doing the math involved in the "Fastest Way in the World to Lose Weight" calculations may be enough to make you lose your resolve and reach for a 150-calorie Twinkie instead.

Realistic Goals

If you want to pursue a more realistic---and healthier---approach to fast weight loss, you can combine a restricted-calorie diet and exercise and aim for a 3 lb. weight loss in a week, triple what you might expect in a moderate plan. The Mayo Clinic, which offers a 1,500-calorie-a-day, 1 lb.-a-day diet for long-term weight loss, says women can safely quick-start their diets by limiting calories to 1,200 a day for a week and men to 1,500.

Counting Calories

Weight loss involves expending more energy than you take in. A pound of fat equals 3,500 calories. When you burn more calories than you need, you lose weight. Women need about 2,000 calories daily to maintain their weight and men about 2,300. If you give up 500 calories a day, you will lose a pound a week. If you give up 1,000, you will lose 2 lbs. The Mayo Clinic, the U.S. Department of Agriculture and most registered dietitians recommend aiming for moderate weight loss for two reasons: it is difficult to obtain proper nutrition on an extreme low-calorie diet, and you can slow your metabolism and regain all your lost weight if you follow such a plan for more than a week.

Adding Exercise

If you want to reach the 3 lb. goal without starving yourself or taking laxatives, you can add exercise to your calorie-restricted diet. Exercise that will mathematically yield a 1 lb. or more weight loss in a week includes running or swimming for an hour a day. If you walk for an hour a day at a pace of 4 miles per hour, you can burn 300 to 450 calories a day, depending on your starting weight. You could lose a pound every seven to twelve days by walking.

Obstacles to Fast Weight Loss

Here's why goals of losing 20, 10 or even 5 lbs. a week are unreasonable: If you limited your food intake to 500 calories a day---not recommended---you would lose 3 lbs. in a week. A 500-calorie-a-day diet would limit you to eating a Big Mac, minus the special sauce. At its most balanced, a 500-calorie-a-day diet would include ½ boiled skinless chicken breast, 1 cup of broccoli, 1 cup of skimmed milk, 1/2 cup of brown rice and an apple. To lose 5 lbs. in a week, you'd have to burn an extra 7,000 calories through such activities as seven hours of running or more than nine hours of jump-roping. A 10-lb. weight loss would require that you run for two hours a day, and a 20-lb. weight loss would require four hours a day.

Certain Foods and Beverages Help

Besides cutting calories and adding exercise, you might give your diet plan an extra edge by including certain foods and beverages. According to Leslie Beck, a registered dietitian who writes regularly for Canada's "Globe and Mail," foods that contain calcium, iron and Vitamin D, which aids calcium absorption, can help you lose weight. She suggests including low-fat dairy, salmon, almonds, seeds and lean meat to your diet or taking supplements. Drinking water may speed your metabolism by as much as 30 percent, according to a study published in 2000 in the "Journal of Clinical Endocrinology and Metabolism." Michael Boschmann, who led the study, compared the effects of drinking water to taking the stimulant ephedrine, an ingredient once popular in weight loss supplements until it was banned. The Mayo Clinic recommends you drink at least six glasses of water daily to remain hydrated.