Total daily energy expenditure (TDEE)
Energy balance—intake vs expenditure—drives body mass change. TDEE is the sum of several components.
Basal metabolic rate (BMR)
Often ~60–70% of daily expenditure—energy for basic functions at rest.
Thermic effect of food (TEF)
- protein ~20–30%
- carbs ~5–10%
- fat ~0–3%
Exercise (EAT) and daily movement (NEAT)
Planned exercise is often only ~5–20% of TDEE for many people. NEAT (steps, chores, standing) can vary by hundreds of kcal/day.
Sex, age, and body composition
Expenditure also depends on muscle mass, age, and sex. Much of age-related decline is lifestyle-related—strength training, protein, and NEAT help.
Women may use a higher fat fraction during aerobic work at matched relative intensity; men may rely more on glycogen at high intensity. Weight change still comes down to total energy balance.
Fuel mix during activity
Fat contribution tends to be higher at low intensity; carbs rise as intensity increases (crossover concept). Weight loss still comes down to long-term energy balance.
BALANS in practice
Consistency and total balance beat chasing a perfect “fat-burning zone.”