This is an excerpt from Secrets of Successful Program Design by Alwyn Cosgrove & Craig Rasmussen.
Daily energy expenditure consists of three components: Resting metabolic rate (RMR minus the sum of BMR plus basic living), diet-induced thermogenesis (DIT), and energy cost of physical activity (see figure 4.1).
Often, when you explain this to potential fat-loss clients, their first instinct is to decide that they will determine their resting metabolic rate (the amount just needed to survive) and only consume calories for that number, or even below. They think that all their additional metabolic demands (the thermic effect of feeding and activities) will create a massive deficit so that they will lose fat rapidly.
While it’s true that the idea of any fat-loss plan is to cut calories and create a gap between intake and output, with the goal of burning fat stores, it’s important to note that when we consume too few calories to support basic functions, the body simply slows down everything because it doesn’t have enough energy to function efficiently.
Extreme low-calorie diets don’t necessarily expend more body fat. Instead, muscle is burned (it’s easier for the body: four calories per gram for muscle (protein) instead of nine calories per gram for fat). Lean muscle is a major factor in resting metabolic rate, so losing muscle will actually cause metabolism to decrease quickly. Maybe someone used to burn 2,000 calories per day at rest, but after losing a few pounds of muscle, now burns only 1,800 calories or so. Therefore, it becomes very easy to eat less than ever but actually gain weight because there is no longer a deficit. At our facility, we have found that the majority of clients, especially women, have a lifetime history of dieting and have lost muscle, as described previously, over and over again by eating low-calorie diets. Eventually, their bodies get to a point where their muscle mass, and therefore metabolism, is so low that previously effective low-calorie diets no longer work, and they decide to hire a professional. By the time they turn to us they usually have a history of low-calorie diets that we have to undo.
Increasing activity levels and increasing muscle, with the result of increasing RMR is a more effective approach than just cutting calories from the diet. Dieting deprives the body of energy, and that works to an extent, but ramping up the system demands is the more effective way to go. Therefore, a metabolic resistance training program is key; this not only increases calories burned, but it also forces the body to recognize muscle, meaning that during a caloric deficit it will burn fat stores, not muscle. Acknowledging muscle as it pertains to exercise is one of the most important factors in changing body composition (body fat to lean tissue ratio). In other words, exercise designed to grow, or at least maintain, muscle (i.e., resistance exercise) is one of the most important factors in an exercise program designed to change a person’s ratio of body fat to total body weight.
In summary, our goal when designing fat-loss programs is to increase metabolic rate to accomplish the following:
- Burn as many calories as possible through resting metabolic rate (lean muscle is metabolically active so building muscle, or at least maintaining it, is extremely important).
- Burn more calories through the thermic effect of food by adjusting meal frequency and manipulating macronutrients. (The thermic effect of protein is twice as high as the thermic effect of fat or carbohydrate.)
- Burn calories through metabolic disturbance (increased activity levels and EPOC).
- Create a gap between total metabolism (calories burned) and intake (calories consumed). In addition, increase calories burned so that calories consumed can be as high as possible. If this situation is met, and adequate protein is consumed and an effective resistance training program is implemented, the body will borrow from its fat stores.