How is energy balance defined?

Energy balance is best defined as the equilibrium between energy intake and expenditure. This concept emphasizes that the body achieves a state of balance when the number of calories consumed through food and beverages matches the number of calories burned through metabolic processes and physical activity. When energy intake exceeds energy expenditure, it results in a surplus, leading to weight gain. Conversely, if energy expenditure surpasses intake, it can lead to weight loss. Understanding this balance is crucial for managing body weight and overall health.

The other definitions touch on specific aspects of energy balance but do not encompass the full concept. For instance, while the ratio of calories consumed to calories burned indicates balance, it lacks the clarity of equilibrium. A surplus of energy stored as fat describes a consequence of a positive energy balance but does not capture the balance itself. The relationship between protein intake and muscle gain is related to nutrition and metabolism but does not pertain directly to energy balance as a whole.