Bigger Leaner Stronger: The Simple Science of Building the Ultimate Male Body

by Michael Matthews

The key to understanding how this works—and to understanding what really drives weight loss and gain—is energy balance, which is the relationship between energy intake (calories eaten) and output (calories burned). Various foods contain varying numbers of calories. For example, nuts are very energy dense, containing about 6.5 calories per gram, on average. Celery, on the other hand, contains very little stored energy, with just 0.15 calories per gram. If you add up the calories of all the food you eat in a day and then compare that number to how many calories you burn in the same period, you’d notice one of three things: You ate more calories than you burned. (Do this often enough and you’ll gain weight.) You ate fewer calories than you burned. (Do this often enough and you’ll lose weight.) You ate more or less the same number of calories as you burned. (Do this often enough and you’ll maintain your weight.)