Breastfeeding Calorie Calculator

The evidence

Every recommendation on this page links here. The badge shows what kind of source it is, so you can judge how strong it is.

1. Guideline

   Sets energy needs in pregnancy (none extra in the first trimester, then more each week) and breastfeeding (about 400 extra a day for the first 6 months: 540 for milk minus 140 from body stores, then 380).

   National Academies (NASEM), 2023, Dietary Reference Intakes for Energy: Dietary Reference Intakes for Energy

2. Guideline

   Publishes the same 2023 equations: the usual equation in the first trimester, a pregnancy equation that rises each week from the second, and 540 minus 140 extra (then 380) while breastfeeding.

   Health Canada, Dietary Reference Intakes tables, equations to estimate energy requirement: Equations to estimate energy requirement

3. Guideline

   Advises total gain for one baby by BMI before pregnancy: 12.5 to 18 kg under 18.5, 11.5 to 16 kg at 18.5 to 24.9, 7 to 11.5 kg at 25 to 29.9, and 5 to 9 kg at 30 or more.

   Institute of Medicine, 2009: Weight Gain During Pregnancy: Reexamining the Guidelines

4. Guideline

   Recommended protein: 0.8 g per kg of body weight a day for adults, 1.1 g per kg in the second half of pregnancy and 1.3 g per kg while breastfeeding.

   Institute of Medicine, 2005 Dietary Reference Intakes (Health Canada tables): Reference values for macronutrients

5. Study

   Measured protein needs in pregnant women directly: on average about 1.2 g per kg early and 1.5 g per kg late in pregnancy, higher than the official average of 0.88.

   Stephens et al., 2015, The Journal of Nutrition: Protein requirements of healthy pregnant women during early and late gestation are higher than current recommendations

6. Guideline

   Without complications, physical activity in pregnancy is safe and good for most women, and is linked to less gestational diabetes and fewer caesarean births.

   American College of Obstetricians and Gynecologists, 2020, Committee Opinion 804: Physical Activity and Exercise During Pregnancy and the Postpartum Period

7. Official data

   Calories for the example foods: a medium banana 105, a 170 g pot of plain nonfat Greek yoghurt 100, a slice of wholewheat bread 80, a tablespoon of peanut butter 95, a cup (240 ml) of 2% milk 120, a 28 g handful of almonds 160.

   US Department of Agriculture, FoodData Central (SR Legacy): FoodData Central

Our own rules of thumb

These are our choices, not findings from a study. We list them so you know which parts are judgement calls.

• The everyday foods are rounded examples of the extra calories.