Glossary
Calorie Deficit
Definition: A state in which energy intake is lower than energy expenditure over a period of time.
Why it matters
It is the underlying energy condition for loss of body mass, but it does not describe food quality, hunger, adherence, body composition, or health impact.
Example
The term may appear in diet descriptions, research summaries, product marketing, or conversations with health professionals. Its practical meaning depends on how it is measured and applied.