It can stop you from eating to much, or to little, for example if you see you've eaten to many calories in a day it can stop you from eating more. It can also convince you too eat a little more if you're under the recommended calorie intake a day. If you're under working yourself it can convince you to work out a little more, but also tell you to take a break if you're overworking yourself.
Proteins are the nutritional class which builds and maintains cells and tissues. The type are often called "structural" since they are like the scaffolding of cells and tissues.
