The Best Weight-Loss Diet: What Does the Science Show? by Jerry Brainum 11/19

Those who seek to lose excessive body fat are faced with a plethora of diet choices. Each diet has its advocates who proclaim that their diet is the most effective at promoting body fat loss. And there is rarely a time when another new fad diet surfaces, often promising to be the ultimate cure for obesity. Often, these various diet plans tout a firm scientific foundation behind them. But skeptical critics of dieting note that if these diets really worked, then why do 97% of those who follow them regain lost weight within a year? Others say simply that for any diet to work, you must experience a deficit of calories ingested compared to how many calories you expend through physical activity. Others even discount the role that exercise plays in promoting more permanent weight loss. They note that when you exercise, your appetite increases. So any calories that you burned by exercise are quickly replaced by food calories. That such statements are ludicrous is easily proved by the sheer number of successful dieters who lost excess fat and kept it off through a combination of exercise and dieting. Indeed, without exercise about half the weight lost through dieting consists of muscle mass. Losing muscle mass is problematic because the extent of muscle mass determines the resting metabolic rate or the number of calories burned at rest. The lower the resting metabolic rate, the lower the rate of caloric burning.

When you begin a diet, it's common to experience a plateau effect that occurs after about 3 to 4 weeks of continuous dieting. This is caused by the body recognizing that you have opted to ingest fewer calories than you normally do. The body responds as if you are in a starvation mode, and makes changes accordingly to prevent the loss of lean mass, mainly muscle mass. One way it does this is by downgrading the production of thyroid hormones. Specifically, the active thyroid hormone known as T3 is converted into a far less active form called reverse T3. The net effect is a significant decrease in the resting metabolic rate. You will experience this as a slowdown in the rate of weight loss. It can be overcome in several ways. One is to increase your activity or exercise level.To effectively alter body composition, you need to exercise at least 4 times a week, doing both resistance and aerobic exercise. Another way to break a dieting plateau is to increase you caloric intake at least twice a week. The final way is to simply overcome the drop in thyroid output by ingesting thyroid drugs. That last solution, however, is the least desirable. For those with occult or undiagnosed heart disease, taking thyroid drugs could impose an additional strain on the heart and pose serious health problems.

So the best plan to lose excess body fat entails a combination of diet and exercise. You must do both to effectively maintain fat loss after the . . .