Final answer:
Each pound of body fat contains around 4,000 kilocalories. Consuming or burning 4,000 kilocalories beyond one's daily energy needs will result in a gain or loss of one pound of body fat, respectively.
Step-by-step explanation:
Each pound of body fat contains approximately 4,000 kilocalories (kcals). Calories, also referred to as big calories or kilocalories, are a measure of the amount of energy available in food. When you eat more calories than your body needs, the excess is stored as fat. Fatty foods are calorie-dense, providing more calories per unit mass compared to carbohydrates or proteins. If you're seeking to maintain weight, your calorie intake must equal the calories you use for energy. Consuming 4,000 kilocalories more than your body requires will result in the gain of one pound of fat. Conversely, to lose one pound of body fat, you must eat 4,000 kilocalories less than your daily energy requirement.