Monday, October 31, 2011
The progression from initial weight loss to a weight-loss plateau follows a typical pattern. During the first few weeks of losing weight, a rapid drop in pounds is normal. When calories from food are reduced, the body gets needed energy by releasing its stores of glycogen, a type of carbohydrate found in the muscles and liver. Glycogen holds onto water, so when glycogen is burned for energy, it also releases the water — about 4 grams of water for every gram of glycogen — resulting in substantial weight loss that's mostly water.
A plateau occurs because your metabolism — the process of burning calories for energy — slows as you lose lean tissue (muscle). When you lose weight, you lose both fat and lean tissue. (The notion that overweight people have a slower metabolism is a myth. In general, the higher a person's weight, the higher the body's metabolic rate.) Your weight-loss efforts result in a new equilibrium with your now slower metabolism. This means that in order to lose more weight, you need to increase activity or decrease the calories you eat. Using the same approach that worked initially will maintain your weight loss, but it won't lead to more weight loss.