The True Cause of Lowered Resting Metabolic Rate after a Diet by Jerry Brainum 3/23

 

 

The resting metabolic rate or RMR is defined as the number of calories your body uses when you are completely at rest. RMR is often used interchangeably with the Basal Metabolic Rate or BMR, but there are slight differences between the two. The BMR refers to the minimum amount of calories used by the body to maintain life functions, such as breathing, cell replication, and maintaining body temperature. The important point about both RMR and BMR is that they don't include any physical activity, such as moving, walking, and exercise. However, the RMR can be influenced by a number of other body processes. These include the thermic effect of food, which refers to the number of calories used to metabolize various nutrients, such as protein, fat, and carbohydrates. Protein produces the highest thermic effect, meaning it uses up the greatest amount of calories in order to be digested and absorbed. Some have suggested that this is one of the reasons why most effective diets to lose excess body fat often emphasize a higher protein intake. A higher protein intake also favorably affects fat loss because it produces an appetite suppressant effect that favors lower food intake, as well as helping to maintain lean mass that is linked to a higher RMR, which means you burn more calories at rest. Dietary fat produces the lowest thermic effect, and again some suggest that this is the reason why fat is the most fattening nutrient besides the fact that it contains the greatest amount of calories at 9 per gram compared to the 4 per gram of carbohydrates and protein.

Exercise also produces a type of thermogenesis, which involves the conversion of calories into heat. Since the thermogenesis process doesn't involve any work or movement, it is also called a futile energy cycle since the calories are not used for anything nor are they stored in the body as fat. Of course, the movement and activity involved in exercise burn a considerable number of calories above the number needed to maintain RMR. This is basically how exercise promotes body fat loss, by burning or oxidizing both ingested calories from food as well as the extra calories used in exercise. If the number of calories you use in physical activity exceeds the number of calories you are consuming from food, the body will tap into stored fat as an energy source. Exercise has come under fire recently as being an ineffective way to lose excess body fat. Exercise skeptics point out that even strenuous exercise doesn't burn a lot of calories, especially when you consider that a pound of stored body fat contains about 3,500 calories. A typical weight workout burns only about 300 to 400 calories depending on the level of exercise intensity as well as the physical size of the person who is exercising. The larger you are, the more calories you burn when you . . .