Low-calorie diets are an important key to winning the battle of the bulge. Armed with a solid understanding of metabolism and calorie-counting, anyone can safely shed pounds and improve overall health.
The only way to lose weight is to burn more calories than you take in. Diet selection and exercise patterns play a part, but weight loss and weight gain are a simple function of the body having too few or too many calories to sustain its normal daily activities.
According to the Mayo Clinic, to lose one pound of body weight, a person must burn 3,500 more calories than she consumes. To lose one pound per week, just burn 500 more calories per day than you take in. The calorie deficit can come from a change in diet, or from exercise, or both.
Mayo Clinic experts recommend eating no fewer than 1,200 to 1,400 calories per day under a normal low-calorie diet, and aiming to lose no more than two pounds per week. Very-low-calorie diets, with daily consumption of 1,000 or fewer calories, can be very effective for rapid weight loss but should be undertaken under a doctor's close supervision.
The first step in figuring out an appropriate calorie-management strategy is to determine your basic calorie needs. The Mayo Clinic provides a free calorie calculator at www.mayoclinic.com/health/calorie-calculator/NU00598.
For example, a 30-year-old male who is 6 feet tall and weighs 200 pounds, and who engages in light physical activity on an average day, needs 2,700 calories to remain at 200 pounds. A 40-year-old female who is 5 feet 6 inches tall and weighs 140 pounds, and who gets moderate physical activity, needs 2,000 calories to maintain her weight.
How much weight can a person lose eating 1,000 calories per day?
If the 30-year-old man started a 1,000-calorie diet, he would have a daily deficit of 1,700 calories (2,700 needed minus 1,000 eaten). In one week, he would lose 3.4 pounds, and more than 13 pounds in a month. The 40-year-old woman would have a daily deficit of 1,000 calories; she would lose two pounds in a week and eight pounds in a month.
Of course, as a person loses weight, his body has less mass to maintain, so the required daily calories also decreases.
Low-calorie diets can be risky if followed for extended periods and should only be started under a doctor's supervision. A doctor will work with you to ensure you get the right mix of nutrients to protect your health. Very-low-calorie diets mixed with vigorous aerobic exercise can put extra stress on the heart and lungs and lead to injury or illness.