Health information & sources

Calorie goals and macros

The iOS app starts with the simplified Mifflin–St Jeor equation for resting energy expenditure, labelled BMR in the app. Weight is in kilograms, height in centimetres, and age in completed years. The published variants are:

• Male: 10 × weight + 6.25 × height − 5 × age + 5 kcal/day.
• Female: 10 × weight + 6.25 × height − 5 × age − 161 kcal/day.

The original study involved healthy adults aged 19–78. This iOS revision limits automatic goals to that age range and those published variants. Other accepted profiles, including “Prefer not to say”, can enter their own targets instead; the app does not invent an intermediate coefficient. Reference 1.

Activity and goal adjustments

CalFood estimates total daily energy expenditure (TDEE) by multiplying the unrounded resting estimate by the selected activity factor: sedentary 1.2, lightly active 1.375, moderately active 1.55, or very active 1.725. It rounds TDEE to a whole kcal, then applies −500 kcal for a lower goal weight, +300 kcal for a higher goal weight, or no change when the weight difference is less than 0.5 kg.

These factors and adjustments are CalFood assumptions, not outputs of the Mifflin paper. They are starting estimates, do not predict a rate of weight change, and may not match your energy needs. The app uses a 1,200 kcal lower input bound and a 10,000 kcal upper input bound. These software limits are not a statement that any intake within them is medically appropriate.

Macro starting proportions

Automatic targets use 20% of calories from protein, 55% from carbohydrate, and 25% from fat. CalFood chooses this starting split within the general adult reference ranges of 10–35%, 45–65%, and 20–35%, respectively. It is not a personalized sports or medical diet. Preference chips do not change these automatic proportions. You can enter different personal targets in Settings. Reference 2.

To convert the calorie proportions to grams, the app divides protein and carbohydrate calories by 4 and fat calories by 9, then rounds to whole grams. Rounding can make the displayed macro energy differ slightly from the calorie target. Reference 3.

You can choose your own targets during onboarding or edit them in Settings. The same calorie input bounds apply, and each macro field accepts 0–2,500 g. These are software input limits, not recommended intakes; manually entered targets are your choices rather than generated recommendations.

Meal and photo estimates

With your permission, Google Gemini estimates food items, portions, calories, and macros from the text you provide. For a photo, a separate first step describes visible foods and approximate portions; that description can be corrected before the nutrition estimate is requested. A photo cannot establish hidden ingredients, exact quantities, or the amount you actually ate.

The AI nutrition pipeline does not retrieve a source record for each result. A model-generated source name is not proof that it looked up that food. The references on this page explain the background calculation methods; they do not certify the numbers for an individual meal. The iOS app shows structured estimates rather than unverified source-sounding AI commentary.

Recipes, cooking methods, oils, portions, and product formulations can change the result. Check the food description and known portions; use the package label or qualified professional guidance when precision matters. Daily totals add up your logged estimates, and saved meals reuse their stored values. Illustrations and example calorie numbers demonstrate the interface and are not measured analyses of the pictured food.

When to use professional guidance

General tracking calculations do not account for every medical condition or circumstance. Seek individual guidance for pregnancy, breastfeeding, growth, recovery from surgery, an eating disorder, or a medically prescribed diet. Automatic calculation eligibility does not establish that weight change is appropriate for you.

A clinician or registered dietitian who knows your circumstances can help you choose suitable targets. The NIDDK planner illustrates why population limits matter; its model is separate from CalFood’s calculation. Reference 4.

References

1. A new predictive equation for resting energy expenditure in healthy individuals

   Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. American Journal of Clinical Nutrition. 1990;51(2):241–247.

   The resting-energy equation and its study population. It does not validate CalFood’s activity multipliers, goal adjustments, or individual meal estimates.

2. Dietary reference intakes tables: Reference values for macronutrients

   Health Canada. Dietary Reference Intakes, Acceptable Macronutrient Distribution Ranges.

   General macronutrient reference ranges for healthy populations. These ranges do not prescribe a unique split for an individual.

3. Food and Nutrition Information Center: macronutrients and calories

   US Department of Agriculture, National Agricultural Library.

   The general energy conversion factors of 4 kcal per gram of protein or carbohydrate and 9 kcal per gram of fat.

4. About the Body Weight Planner

   National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. Last reviewed May 2017.

   Why the intended population and professional guidance matter for weight planning. CalFood does not implement the NIDDK planner or its validated model.