One pound has 3,500 calories in it. So, for each pound you wish to lose, you must create a 3, 500-calorie deficit. You can achieve a calorie deficit through dieting alone, or dieting and exercise. Extreme weight loss results from calorie restriction and monitoring the foods in your diet.
Calories
Before you begin cutting calories, you should first determine how many calories your body uses or needs daily. Use an online calorie calculator to help you determine this number. Make sure the calculator takes into consideration age, sex, height, current weight and activity level. Once you know how many calories you should eat each day, you can begin to decrease this number to result in your desired weight loss.
Nutrition
Choose naturally low-calorie foods over their processed counterparts. For example, get your carbohydrates from fruits and vegetables instead of white bread, cereal and pasta. Processed carbohydrates are easily digested and interfere with weight loss and even promote weight gain, notes Harvard School of Public Health. Get your fats from vegetable sources, like nuts, seeds and avocados, rather than from fatty meats or packaged, baked or fried foods. Eating healthy fats daily aids in sustained weight loss notes nutritionist Ann Louise, and provides satiety to meals — helping you eat less food and fewer calories. On this extreme weight loss diet, make sure you are getting enough protein. Protein will help preserve your lean muscle mass, ensuring the majority of weight loss will be fat, not muscle.
Effects
Extremely low-calorie diets, fewer than 1,200 calories for women and 1,500 calories for men, cause fatigue, constipation, nausea, diarrhea and, most often, the development of gallstones. Weight regain is often shown with low-calorie diets. On an extremely low-calorie diet your body will adjust to this caloric intake so it can function off of fewer calories — a slower metabolism. But once you return to a normal diet, your metabolism will still be low functioning, causing weight gain, notes the Weight-Control Information Network.
Risks
Low-calorie diets have been associated with the development eating disorders, such as anorexia nervosa or bulimia nervosa, because such an emphasis is placed on calories and not on healthy nutrition. These psychological disorders result in an altered body image for the dieter, according to the University of Maryland Medical Center. The development of an eating disorder can also lead to depression, anxiety and substance abuse. Left undiagnosed and untreated, anorexia and bulimia can cause heart and kidney problems and even death, notes MedlinePlus.
Risks
Long-term and effective weight loss does not come from extreme diets but rather a change in lifestyle and monitoring your eating habits. A healthy diet rich in a variety of foods and nutrients and daily exercise is the most successful way to lose weight and keep it off. Healthy weight loss is considered to only be 1 to 2 lbs. per week.
