Energy Balance
The science behind weight management is complex, but one of the key concepts that governs weight management is Energy Balance. Energy Balance is the phrase used to describe the difference between the number of calories a person consumes and the number of calories that same person expends (a.k.a. burns) in a given time period. There are three possible scenarios when it comes to the energy balance equation:
Calories consumed (food, drink) = Calories expended (basal metabolic rate, physical activity, thermogenic effect of food, acute illness)
Outcome: Weight remains unchanged
Calories consumed > Calories expended
Also known as Positive Energy Balance
Outcome: Weight increases
Calories consumed < Calories expended
Also known as Negative Energy Balance
Outcome: Weight decreases
Source Wikipedia