Gram-Based Logging

Gram-based logging is entering food portions in grams — the metric system — instead of the U.S. household measures (cups, tablespoons, fluid ounces) that most American cookbooks use. It's the default unit in most nutrition databases, including USDA FoodData Central, and it's the unit that gives you the most accurate log.

Why databases prefer grams

Nutrition science uses mass, not volume. When USDA publishes the nutrition profile of "cooked long-grain white rice," the figures are per 100g. When a European manufacturer prints a nutrition label, it's per 100g. When a researcher publishes a study on protein intake, it's in grams per kilogram of body weight. Grams are the lingua franca. Converting back to cups is where error creeps in.

The density problem (one more time)

Cups are volume. Volume doesn't tell you mass unless you know density, and food density varies wildly:

• 1 cup of chopped broccoli ≈ 90g
• 1 cup of shredded cheese ≈ 110g
• 1 cup of granola ≈ 100g
• 1 cup of dense granola with nuts ≈ 140g
• 1 cup of packed brown sugar ≈ 220g

Grams skip the whole conversion step. A gram is a gram.

Switching your app to grams

• Cronometer: already gram-first for most foods. No action needed.
• MacroFactor: already gram-first where manufacturer data supports it.
• MyFitnessPal: tap the unit dropdown on each food entry — it'll usually offer grams even if the default is "1 serving."
• Lose It!: similar to MyFitnessPal — gram option is there, not always default.
• Yazio: toggle grams in settings or on a per-food basis.

When the database doesn't have gram data

Some user-submitted entries only list volume units ("1 slice"). If grams aren't offered for the food you need, you have three options: find a verified or manufacturer-sourced entry that does have grams; create a custom entry from the label; or log in volume and accept the precision tradeoff.

Ounces, grams, and the U.S. label

U.S. nutrition labels show grams for macronutrients (protein, carbs, fat, fiber) but often show oz or fl oz for the serving size. The "grams" on the label are nutrient grams, not portion grams — a common source of confusion. "Serving size: 1 cup (245g)" means 245g is the serving weight; the 12g of protein below refers to 12g of protein in that 245g portion.

A practical setup day

Fifteen minutes, once: go through the first week of foods you log regularly and make sure each entry is keyed to grams. After that, the scale-to-grams-to-app workflow is ten seconds per food, forever. The accuracy upgrade compounds over every future meal.