This is because the muscles are active and continually need to burn calories. Since we now have less muscle mass, your body metabolism slows losing some of the ability to burn calories.
In other words, when you get back to your weight unless you exercise you’re putting in your body fat instead of muscle. You will be fatter and less healthy than before low-crab diets. To make matters worse, muscle tissue is looser and not act as a fat burner and noticed a decline in your metabolism and therefore calories burned will be less, the result back fat.
Since then I have been out of the low-crab diets. Sin low-crab diets we require you to drastically reduce the consumption of carbohydrates. The Atkins diet went a step further, to defend the almost non-consumption of carbohydrates for 2 weeks before adding some crabs in your meals gradually.