According to The American College of Sports Medicine (ACSM) a healthy weight loss is 1-2 pounds per week. Faster weight loss diets are not healthy because you don’t want to lose muscle, right? I know that you often see headline like ‘lose 10 pounds in 11 days’, ‘lose 10 pounds in a week’ and ‘lose 15 pounds in 4 days without any exercise’. Headlines like that are so frequent that they must state the truth. Well, they don’t, instead they mislead you.
If you lose 10 pounds in a week it is not healthy for you, let’s divide your weight loss into categories of water, muscle and fat. A fast weight loss of 10 pounds means that you have lost approximately 2 pounds of fat, 4 pounds of water and 4 pounds of lean muscle. Did you know that? What happens when you stop dieting? You will gain the water weight (remember that the body consists of 70% water and it strives to be well-balanced). You lost 2 pounds of fat which is great but you also lost 4 pounds of lean muscle-mass. It is a lot easier to gain weight fast and that weight gain consists of fat because it takes longer to build muscle-mass.
Basically, in the long run, you have lost 10 pounds only to gain them again and you also replaced 4 pounds of muscle with 4 pounds of fat. Seems like a good idea? That doesn’t even have to be answered.
Let’s go back to what the ACSM writes in their guidelines. A healthy weight loss should be no greater than 1-2 pounds per week, 1-2 pounds of fat that is. You do not want to lose muscle and you do not want to lose water.
If you want to lose 40 pounds of fat it should take at least 20 weeks. Losing the weight in fat takes time because your body can only burn so much fat at a time. Losing 2 pounds every week means that you should use a diet that increases the metabolism of fat.
There are lots of diets that do this and in every other ad you see they tell you that exercise is not a necessity for this to work. Let me tell you, our body is the product of thousands of years of evolution and it tries to improve through every generation. If you want to keep muscle-mass it means that you have to use the muscle you have or else it will be metabolized into energy instead of your fat. The body wants to keep storage of energy and that energy is stored in fat. The body does this to have a reserve in case of a starvation period. On the other hand, if you exercise during your diet, your body knows that you already need the muscle-mass you have and instead it uses the fat for energy. Makes sense?