FortiorNutrition
Calories and macros: how protein, carbs and fat add up
To count macros, add up the grams of protein, carbohydrate and fat in your food. Calories follow from the grams: 4 per gram of protein and carbohydrate, 9 per gram of fat. Fortior does the adding for each meal and each day.
Where the calories in food come from
Food calories are kilocalories (kcal), and they come from three macronutrients: protein, carbohydrate and fat. Each carries a standard amount of energy per gram. That is why a gram of fat has more than twice the calories of a gram of protein or carbohydrate.
| Macronutrient | Calories per gram | Example |
|---|---|---|
| Protein | 4 | 30 g = 120 kcal |
| Carbohydrate | 4 | 50 g = 200 kcal |
| Fat | 9 | 15 g = 135 kcal |
These are rounded, widely used conversion factors. Package labels round their numbers and may treat fiber, sugar alcohols or alcohol differently, so calories worked out from macros can land a little away from the number printed on the package. Both are estimates.
How to count macros
Counting macros means adding up the grams of protein, carbohydrate and fat in what you eat.
- Find the grams for each food. Use the package label or a food database, scaled to the amount you ate. Weighing food in grams is the most precise way to scale it.
- Add each macro across foods. A meal or day total is the sum of the grams.
- Convert to calories if you want the energy split. Multiply each total by its calories per gram.
A worked example
A meal has 30 g of protein, 50 g of carbohydrate and 15 g of fat.
| Macronutrient | Grams | Calories | Share of the meal |
|---|---|---|---|
| Protein | 30 | 30 × 4 = 120 | 120 ÷ 455 = 26% |
| Carbohydrate | 50 | 50 × 4 = 200 | 200 ÷ 455 = 44% |
| Fat | 15 | 15 × 9 = 135 | 135 ÷ 455 = 30% |
| Total | 95 | 455 | 100% |
Fat is the smallest amount in grams but supplies about 30% of the calories, because every gram counts for 9.
Percentages and grams: two ways to talk about macros
Public health guidance usually describes macros as a share of calories. The U.S. Dietary Guidelines, for example, cite ranges for adults of roughly 10–35% of calories from protein, 45–65% from carbohydrate and 20–35% from fat. Sports nutrition sources more often use grams, sometimes relative to body weight.
These are population-level reference points that people commonly cite, not a recommendation for you. Fortior does not choose a split for you. You enter your own targets, and a registered dietitian or coach can help you decide which numbers suit your situation.
How Fortior shows calories and macros
Fortior adds up what you log at three levels:
- Per day. Daily progress lists Energy, Protein, Carbohydrate, Fat and, when you have logged or targeted it, Fiber and Fluids. Each row shows what you logged against your target, such as 1,850 / 2,230 kcal. Without a target it shows the total alone.
- Per meal. The By meal card lists each meal you logged, such as Breakfast, Lunch, Dinner, Snacks or a pre-, intra- or post-workout meal. Each line shows its calories, its share of the day's calories, and its protein, carbohydrate and fat. The card header shows the day's calorie total.
- Per food. Open a meal in the Meals list to see the energy and macros of each food in it, and to change its servings.
Two behaviors are worth knowing. A missing nutrient is unknown, not zero: a meal whose foods report no calories reads "Calories not reported" instead of 0. And a day is treated as a partial log until you tap I'm done logging today under Food log status, so a half-logged day is not mistaken for a day of eating little.
Setting calorie and macro targets
Enter a target for each macro in grams, and Fortior works out the calories with the same 4, 4 and 9 factors.
- On the Nutrition tab, scroll to Library and preferences, tap Targets, then tap New target.
- Enter protein, carbohydrate and fat in grams. Fortior shows the calories as "Calculated from macros". To type calories yourself, tap Enter calories manually.
- Optionally add fiber and hydration targets.
- Choose when the target applies (Every day, Training day, Rest day or Event day) and the date it takes effect.
Those figures only show the arithmetic. They are placeholders, not a suggestion. The target screen also says that targets support general wellness and training planning, and that Fortior does not diagnose conditions or prescribe medical diets.
Fortior picks the day type from what you logged. A finished workout makes it a Training day, a workout logged as a competition makes it an Event day, and a day without a workout is a Rest day. A target for that day type is used before an Every day target.
Keeping the numbers honest
- Barcode, label and database entries start from reported values. Meal photo estimates are estimates and can miss portions or ingredients, so review them before you save.
- When you review a label scan or photo estimate, Fortior flags an item whose reported calories differ widely from the calories implied by its macros, so you can re-check it.
- Daily totals that arrive from Apple Health appear in Daily progress but not in By meal, because they come without meal detail.
In the app: open the Nutrition tab. Daily progress and By meal are on that screen. Set targets under Library and preferences, then Targets.
Nutrition information here is educational and based on the food you log. It is not medical advice, and Fortior does not diagnose conditions or prescribe medical diets.