You should realize that the weight loss experienced during the early part of a strict diet program is usually a loss of water, not fat. Many diets restrict carbohydrate intake. This reduces the water content of the body because much of the water stored in our bodies is accumulated in the process of storing carbohydrates. Weight loss due to the reduction of water stores is only temporary. Once the fluid balance is restored, the weight scale does not reflect the loss of body fat that was assumed to have occurred.
Muscle Tissue Loss
Also, if a female dieter consumes less than about 1,200 kilocalories a day (1,500 kilocalories a day for a male), muscle tissue as well as fat is usually lost. The farther the caloric intake dips below this amount, the more muscle tissue is lost compared to fat. So even though the dieter loses weight, he or she is actually fatter because the percentage of body fat compared to that of lean body weight has increased. The goal of a sound diet should be to reduce total body weight without losing muscle tissue. People who are on the roller coaster of dieting, gaining weight, and dieting again may be weakening their body every time they diet. This ”yoyo” approach is the wrong way to lose weight; it has a negative effect on the body, and it is ineffective for maintaining an appropriate level of body fat.
Body Size Considerations
It appears that many overweight people justify their overeating by thinking that because their bodies are heavy, they need more food to nourish them. Actually, the opposite is true in many cases. Too much of their body weight is fat, which, unlike muscle, is not as metabolically active. In contrast, exercising muscles burn calories; the more muscle there is, the more energy is expended and the faster stored fat is reduced.
Compare two individuals who are the same height, one of whom weighs more and is in worse physical condition than the other. The lighter person has more muscle and less stored fat due to a good fitness level, and will require a greater caloric intake than the less active, heavier, fatter, and less muscular person.
Values of Weight Training and Aerobic Exercise
For many, the most effective way to decrease excess body fat is to moderately reduce caloric intake while participating in an aerobic and weight training program.
These exercise programs will burn calories and maintain or build muscle tissue, which encourages an improvement in the fat to muscle
ratio. In 40 minutes of aerobic exercise, the average individual burns approximately 400 to 480 kilocalories. Keep in mind that aerobic activities involve the large muscles in continuous activities such as in cycling, swimming, walking, jogging, cross country skiing, and rope skipping. These activities promote the greatest caloric expenditure. Golf, on the other hand, is not a continuous and rhythmic activity and burns only half the calories that swimming the backstroke does for individuals of the same body weight.
Weight training sessions do not typically expend as many calories as aerobic exercise sessions, but they do maintain or increase muscle mass. This is important because by adding more muscle more calories are burned.
Losing Fat Weight
If you want to lose body fat, attempt to lose it at a maximum rate of 1 to 2 pounds per week. Losses greater than this result in losses of muscle tissue. A pound of fat has approximately 3,500 kilocalories, so a daily dietary reduction of 250 to 500 kilocalories will total about 1,750 to 3,500 kilocalories a week. Combined with regular exercise, this will promote the recommended loss of 1 to 2 pounds of fat per week and help keep it off.
Gaining Fat Free Weight
Most people who exercise have no interest in gaining body weight; however, there are some who participate in weight training programs specifically to gain muscle. To accomplish this, there needs to be an increase in caloric consumption in combination with regular training. The weight training will stimulate muscle growth, and thus body weight increases. The consumption of additional calories (beyond one’s daily needs) provides the basis for the increase in muscle tissue. The addition of 1 pound of muscle requires 2,500 kilocalories more than normal metabolic needs. An equal increase in proteins and carbohydrates (with a special emphasis on complex carbohydrates) and a maintenance of fat intake should help promote lean tissue growth and an increase in muscle size.
Note that a woman typically does not become as muscular as a man, so it is unlikely that she will significantly gain body weight in response to weight training unless she makes an effort to do so (by increasing food intake and following a program designed to develop hypertrophy).