How Sweatmeal calculates your numbers

Sweatmeal builds your daily calorie and macro targets from how you actually trained, not a flat formula. Burn comes from a wearable when you have one; your calorie target cycles around training load; protein and fat anchor to a fat-adjusted weight instead of raw bodyweight; carbs are whatever's left — the energy you earn. Every number says whether it's measured or estimated.

Your target has a temperature: it eases on rest days and opens up around hard training and race week.

How do you calculate my daily burn?

Your daily burn comes straight from your wearable when one is connected. Without a wearable, it starts from a validated resting-metabolism equation(Mifflin–St Jeor) scaled by your activity, then refined by your weight trend over time — so the longer you use Sweatmeal, the more accurate the number gets.

Whoop, Strava, Oura, and Ultrahuman connect through Open Wearables; Apple Health (and Android Health Connect) is read on-device. Any of these give you a measured burn instead of an estimate, so connecting one gives you the most accurate burn number Sweatmeal can produce.

How do you calculate my calorie target?

Your goal — lose, maintain, or gain — sets a daily deficit or surplus. That deficit or surplus is then cycled around your training: bigger on rest days, smaller on hard training days, so you're not running a hard session on the same restriction as a day off.

Low recovery eases the target further, because a body that hasn't recovered doesn't benefit from a bigger deficit. Whatever the goal, the target never drops below your RMR (resting metabolic rate) — the floor is non-negotiable.

How much protein do I need?

Protein is set per kilo of your fat-adjusted weight, not your raw bodyweight — following the ISSN position stand on protein and exercise, which sets protein by body mass and raises it further when you're in a deficit. This is the anchor the rest of your macros are built on.

If you've entered a body-fat percentage
Protein and fat are set per kilo of your lean mass.
If you haven't entered a body-fat percentage
Protein and fat are set per kilo of an ideal weight estimated from your height.
In a deep cut
Protein rises further, to protect muscle while you're losing scale weight faster.

Why anchor protein on fat-adjusted weight instead of bodyweight?

Because extra body fat doesn't need extra protein to maintain — only lean tissue does. Setting protein per kilo of raw bodyweight over-targets someone carrying more fat and under-targets a lean, muscular athlete carrying very little. Anchoring to a fat-adjusted weight keeps the target honest for both, rather than rewarding or punishing body composition it never actually measured.

How are my carbs set?

Carbs are whatever calories are left once protein and fat are set — the energy you earn from training, not a fixed ratio. Training days keep a carb floor so performance never suffers, an approach sports scientists callfuelling for the work required, and that floor lifts further around a race for a carb-load.

How confident are these numbers?

We say so when a number is an estimate rather than something measured. Body-fat percentage, ideal weight from height, and burn without a wearable are all estimates — useful starting points, not facts. Connect a wearable, and let your weight trend refine the rest over time, and the numbers sharpen from estimated to measured, which is when they're most worth trusting.

How we calculate — quick answers

How do you calculate my daily calorie target?
Your goal sets a daily deficit or surplus, then it is cycled around your training — bigger on rest days, smaller on hard ones — and eased further when your recovery is low. The target never drops below your RMR (resting metabolic rate), no matter how aggressive the goal.
How much protein do I need?
Protein is set per kilo of your fat-adjusted weight, not your raw bodyweight — your lean mass if you have entered a body-fat percentage, otherwise an ideal weight estimated from your height. Protein rises further in a deep cut to protect muscle.
Why do you use my fat-adjusted weight instead of my bodyweight for protein?
Extra body fat doesn't need extra protein to maintain — only lean tissue does. Anchoring protein to raw bodyweight over-targets people carrying more fat and under-targets lean, muscular athletes. A fat-adjusted weight keeps the number honest for both.
How are my carbs calculated?
Carbs are whatever calories are left after protein and fat are set — the energy you earn from training. Training days keep a carb floor so performance never suffers, and the floor lifts further around a race for a carb-load.

The science this is built on

These targets are engineered from peer-reviewed methods and the position stands nutrition scientists actually use — not a proprietary black box. The reasoning above draws on:

  1. Resting metabolism — the Mifflin–St Jeor equationMifflin, St Jeor et al., American Journal of Clinical Nutrition (1990)
  2. Validated against measured metabolism (indirect calorimetry)Bias and accuracy of RMR equations, Clinical Nutrition (2013)
  3. Maintenance energy — physical activity level (PAL)FAO/WHO/UNU, Human Energy Requirements
  4. Why weight change is dynamic, not a flat 3,500-kcal ruleHall et al. (dynamic energy balance), International Journal of Obesity
  5. Why your burn adapts as you lose weight (metabolic adaptation)Trexler, Smith-Ryan, Norton, Metabolic Adaptation to Weight Loss, JISSN (2014)
  6. Macronutrient ranges (AMDR)National Academies, Dietary Reference Intakes
  7. Protein by bodyweight and lean mass — higher in a deficit to protect muscleJäger et al., ISSN Position Stand: Protein and Exercise, JISSN (2017)
  8. More protein preserves lean mass during a calorie deficitHelms et al., protein during caloric restriction in lean athletes, IJSNEM (2014)
  9. Carbohydrate scaled to the training demands — 'fuel for the work required'Impey et al., Fuel for the Work Required, Sports Medicine (2018)
  10. Food energy conversion (Atwater 4-9-4-7 factors)FAO, Calculation of the energy content of foods

Predictive equations are estimates, not measurements — indirect calorimetry is the gold standard, and Sweatmeal recalibrates against your real results over time. This is nutrition information, not medical advice.