The hormone insulin is quite odd in its activity. It likes to store different stuff. The only problem is that sometimes it makes your muscles grow and sometimes it makes your fat cells grow. Different foods create diverse insulin responses. Foods that have high–glycemic index rankings ( white bread, most cereals, grapes, bananas) dump a lot of sugar into your bloodstream after the meals, making insulin levels to spike. In this case, insulin works rapidly to turn that blood sugar into fat.
Other foods, though, cause a different reaction. Dairy products (milk, yogurt, ice cream) create dramatic insulin surges without the related effect on blood sugar. You also get this insulin reaction from some foods that are virtually carbohydrate-free, such as beef and fish, which have hardly any action on blood sugar. When blood sugar remains rather constant, it allows insulin to use the nutrients in your blood to build and restore cells, including muscle tissue.
That’s why there are diets that centers on high-fiber, nutrient-dense foods that are also the ones considered to be most useful for weight loss. Most are restrained to high protein, some are high in dairy calcium, and those that are carb-based emphasize fiber and other vital nutrients.