Basal Metabolic Rate (BMR)
TDEE & calorie targets
Suggested macros (maintenance)
Macros based on: protein 2 g/kg, fat 25% of calories, remaining calories from carbs.
What is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day, including physical activity. It is calculated by multiplying your Basal Metabolic Rate (BMR) by an activity multiplier.
BMR formulas used
- Mifflin-St Jeor: the current gold standard, recommended by the Academy of Nutrition and Dietetics. Most accurate for the general population.
- Harris-Benedict (revised): the classic formula, slightly overestimates compared to Mifflin-St Jeor.
- Katch-McArdle: the most accurate formula if you know your lean body mass (LBM). It calculates BMR from LBM directly, so it applies equally to all body compositions.
Activity multipliers
| Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Desk job, no structured exercise |
| Lightly active | 1.375 | Light exercise 1-3 days per week |
| Moderately active | 1.55 | Moderate exercise 3-5 days per week |
| Very active | 1.725 | Hard exercise 6-7 days per week |
| Extra active | 1.9 | Physical job or twice-daily training |
Using your TDEE
- Maintenance: eat at TDEE to maintain current weight
- Weight loss: create a deficit of 300-500 kcal/day for ~0.3-0.5 kg/week loss; a deficit of 500 kcal/day = ~1 lb/week
- Muscle gain: eat 300-500 kcal above TDEE with adequate protein (1.6-2.2 g/kg body weight)
UK and US reference intakes, and why they differ
| Reference | Women | Men | Basis |
|---|---|---|---|
| UK NHS | 2,000 kcal | 2,500 kcal | Sedentary reference adult |
| US FDA | 2,000 kcal | 2,500 kcal | Same, used for Nutrition Facts labels |
| WHO | ~1,800-2,100 kcal | ~2,200-2,600 kcal | Range by age and activity |
The UK Eatwell Guide (not "food pyramid", the NHS uses a plate model) recommends: more fruit and veg (at least 5-a-day), starchy carbohydrates, dairy or alternatives, protein foods, and small amounts of unsaturated oils. It does not include a calorie recommendation, the TDEE calculation fills that gap.
The ultra-processed food (UPF) problem, most relevant in the UK
The UK has one of the highest rates of ultra-processed food consumption in Europe, around 57 % of calories in UK adult diets come from UPF (NOVA classification). Research (including studies from Imperial College London and UCL) consistently links high UPF consumption to obesity, metabolic disorders, and shorter lifespan, regardless of calorie intake. Knowing your TDEE is useful, but the quality of those calories matters too: 2,000 kcal of ultra-processed food is not equivalent to 2,000 kcal of whole foods for long-term health.
TDEE is an estimate. Track actual weight change over 2-4 weeks and adjust. Individual metabolism varies by 10-20%.