- BMR (Basal Metabolic Rate): This is the amount of calories you need to consume to maintain your body if you were comatose (base level)….
- NEAT (Non-Exercise Associated Thermogenesis): The calorie requirements added by your daily activity that is NOT exercise (eg: washing, walking, talking, shopping, working). This is generally the most marked variable in a persons daily calorie requirements and something that everyone has a good amount of control over. This is what people term INCIDENTAL EXERCISE. It is also what helps keep ‘constitutionally lean’ people LEAN (they fidget)!
- EAT (Exercise Associated Thermogenesis): The calorie requirements associated with planned exercise…. Unless someone is doing a whole heap of exercise (eg: two or more hrs training a day) it usually doesn’t add a stack of calories to your requirements (30 minutes of ‘elliptical training isn’t going to do it’)
- TEF (Thermogenic effect of feeding): The calorie expenditure associated with eating…. REGARDLESS of what myths you have been told - this is NOT dependent on MEAL FREQUENCY. It is a % of TOTAL CALORIES CONSUMED (and 15% of 3 x 600 cal meals is the same as 15% of 6 x 300 cal meals). It varies according to MACRONUTRIENT content and FIBER content… For most mixed diets, it is something around 15%…. Protein is higher (up to 25%), carbs are variable (between 5-25%), and fats are low (usually less than 5%). So -» More protein and more carbs and more fiber = HIGHER TEF. More FAT = LOWER TEF.
- TEE (Total Energy Expenditure): The total calories you require - and the sum of the above (BMR + NEAT + EAT + TEF).
How much do you need?
There is therefore a multitude of things that impact a persons MAINTENANCE calorie requirements
- Age and sex (males generally need > females for any given age)
- Total weight and lean mass (more lean mass = more needed)
- Physiological status (eg: sick or injured, pregnant, growth and ‘enhancement’)
- Hormones (eg: thyroid hormone levels, growth hormone levels)
- Exercise level (more activity = more needed)
- Daily activity level (more activity = more needed)
- Diet (that is - macronutrient intake)
In order to calculate your requirements the most accurate measure would be via Calorimetry [the measure of ‘chemical reactions’ in your body and the heat produced by these reactions], either directly (via placing a calorimeter where the heat you produce is measured) or indirectly (eg: HOOD studies where they monitor how much oxygen you use/ carbon dioxide and nitrogen you excrete over a given time). Although accurate - this is completely impractical for most people. So we mostly rely on pre-set formula to try to calculate our needs.
Read more to see how to estimate your requirements and get the right macro-nutrients in your diet.