There are 4 calories per gram of protein and carbohydrates. (leanhybridmuscle.com)
Obesity was assumed to be due to an excess of calories, and fat has more calories per gram than carbohydrates or protein, so eating fewer calories was easier if you cut fat. (peoplesrx.com)
People are often surprised to learn that dried pet foods have about four times as many calories per gram as wet foods. (mypetreference.com)