How we work out what you need

1. Resting metabolism

   It starts from your basal metabolic rate, the energy your body uses at rest. We use the Mifflin-St Jeor equation, one of the most reliable for adults:

   Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

   If you prefer not to say your sex, we use the value halfway between the two (−78).

2. Your day

   We multiply the basal rate by a factor describing your daily life, work and getting around, without counting workouts:

   Sedentary · desk job, little movement	× 1.4
   Lightly active · on your feet for part of the day	× 1.55
   Active · active job, on your feet for hours	× 1.7
   Very active · heavy physical work	× 1.9

   These are lower than the classic physical activity levels, because those already include some exercise: we add workouts separately.

3. Workouts

   Each workout adds the energy it uses on top of resting, worked out with the MET values of the 2024 Compendium of Physical Activities:

   (MET − 1) × weight (kg) × duration (hours)

   We count 75% of it: MET formulas tend to overestimate, and eating back every calorie burned is the most common way a deficit disappears. Until you log workouts, we start from the ones you plan, 45 minutes at medium intensity each.

4. Your goal

   Maintenance (your day plus workouts) is adjusted to what you want to achieve:

   Lose weight	−17%, at most −500 kcal
   Maintain weight	maintenance
   Build muscle	+10%

   The result is rounded to 10 kcal and never goes below 1,200 kcal. If a nutritionist follows you, they set the target.

5. Macronutrients

   Protein follows body weight, not calories, so it doesn’t drop when you are in a deficit:

   Protein	1.4 g per kg to maintain weight, 1.6 g per kg to lose weight or build muscle (between 10% and 35% of calories)
   Fat	30% of calories
   Carbohydrates	the rest

   You can change the split in the app’s settings.

6. From needs to plate

   The day’s calories are split across meals:

   Breakfast	20%
   Snack	10%
   Lunch	30%
   Afternoon snack	10%
   Dinner	25%
   Evening snack	5%

   For each meal we pick a suitable recipe and scale it to you, from half a serving to two servings in 5% steps, so quantities stay realistic and each meal stays within 15% of its share. If you skip a meal, its share goes to the others.

7. Weight over time

   To estimate when you will reach your target weight we use the approximation of 7,700 kcal per kilo: 300 kcal a day below maintenance is about 0.27 kg less per week. It is an estimate: real weight fluctuates, which is why the calculation updates with every weigh-in.

skish is not a medical device and does not replace the advice of a doctor or a nutritionist. If you are pregnant, breastfeeding, or have a medical condition or an eating disorder, talk to a professional before following a plan.