Your total daily burn is shaped by basal metabolism, food digestion, and activity. Muscle raises resting burn slightly; body size and activity dominate. "Boost metabolism" shortcuts (special teas, ice water) have tiny effects. The reliable levers are building muscle, moving more (NEAT), and preserving lean mass in a deficit. Severely low calories can lower resting burn over time — another reason moderate deficits beat crash diets.
Key facts:
- BMR + digestion + activity = total
- Muscle slightly raises resting burn
- NEAT is a big variable
- Crash diets lower burn