energy_expenditure_calculator
Work out maintenance calories (TDEE), BMR, and a target for a goal.
Use for: 'how many calories should I eat', 'what is my TDEE', 'calorie
deficit to lose weight', 'how many calories to lose 5kg', 'what are my
macros'.
NAME THE FORMULA. Mifflin-St Jeor and the revised Harris-Benedict differ by
5 to 10% for the same person, which is often more than the entire deficit
they are trying to run. formula_spread_kcal is that gap and
bmr_formula_used says which one the answer took. Quoting a calorie number
without saying where it came from is the mistake to avoid here, because the
person will treat it as measured rather than estimated.
ASK FOR BODY FAT IF THEY MIGHT KNOW IT. With it, Katch-McArdle works from
lean mass and is the better estimate, particularly for anyone muscular or
carrying more fat than average, where the weight-based formulas are worst.
WARN ABOUT THE ACTIVITY LEVEL. Most people overestimate it, and one level
is worth several hundred calories a day. One level lower than it feels is
usually closer.
Projections use 7,700 kcal per kilogram of body fat, so 500 kcal a day is
about half a kilogram a week. Pass on the caveats: these are population
formulas, not a measurement, and a long timeline runs optimistic because
metabolic rate falls as weight does. The honest advice is to eat at the
number for two to three weeks and adjust from what the scale does.
Args:
sex: male or female. It changes the formula constant.
age: Years.
weight_kg: Body weight in kilograms.
height_cm: Height in centimetres.
activity_level: sedentary, light, moderate, very_active, extra_active.
goal: lose, maintain or gain.
body_fat_pct: Optional, and worth asking for.
target_weight_kg: Optional, produces a timeline.
Returns:
All three BMR formulas with their spread, the TDEE, a calorie target
for the goal, protein, fat and carbohydrate targets, and a timeline to
any target weight.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| age | Yes | ||
| sex | Yes | ||
| goal | No | maintain | |
| height_cm | Yes | ||
| weight_kg | Yes | ||
| body_fat_pct | No | ||
| activity_level | No | moderate | |
| target_weight_kg | No |