You can look and feel great without breaking out a calculator every time you eat.
Getting proper nutrition is a precise science, but it doesn’t have to be agonizing. In fact, I recommend a more laid-back approach. If you make planning or tracking meals too complicated, you’ll have trouble sticking with it.
That being said, in order to lose fat, you must keep your body burning more energy than you’re feeding it, and the energy potential of food is measured in calories. Eat too many calories—give your body more potential energy than it needs—and it has no incentive to burn fat.
In order to gain muscle, your body needs a surplus of energy to repair and rebuild itself (along with plenty of protein). Thus, you need to eat slightly more than your body burns to get bigger.
just by following this simple rules, you’ll find that you can lose or gain weight when you want to and that you’ll feel healthy and vital.