Eat your number. Don't diet off it.
In the first 6 months of nursing only breast milk, making milk costs about 540 calories a day. Your body pays 140 of those from the fat it stored in pregnancy, so the calculator adds 400, not 540. That 140 a day works out to about 0.64 kg (1.4 lb) a month coming off while you eat your number.
So while your baby is under 7 months, don't cut calories from this number to diet. The 140 from stored fat is already the cut, so you'd be cutting twice. From 7 months, the calculator adds 380 for milk and takes nothing off for stored fat, so your number holds your weight steady.
It's a starting point. Weigh yourself once a week at the same time of day, and move your number up or down if the scale says it's off.
Why one source says 330 and another says 500
Search for how much more to eat while breastfeeding and you'll see 330, 400, 450 and 500. They mostly agree. The big difference is whether they take off the calories your stored fat covers.
The Dietary Guidelines for Americans add 330 to what you ate before pregnancy in the first 6 months, if you started at a healthy weight: 500 for milk, minus 170 for weight loss. In the second 6 months they add 400 and assume your weight is steady. The CDC's range of 330 to 400 matches those two numbers. The 2023 National Academies report does similar math and gets 400, then 380. ACOG's 450 to 500 is what it says your body needs to make milk.
If you want to lose weight faster
Strong, not starving. The Academy of Nutrition and Dietetics says women who eat less than 1,800 calories a day may make less milk, and calls 1 pound a week a safe goal for breastfeeding moms who want to lose weight. If your milk supply seems to drop, eat more and talk to your doctor or a lactation consultant.
Carrying extra weight from before pregnancy? The Dietary Guidelines say to work out your number with your healthcare provider. Whatever your weight, check with your doctor before you change what you eat, especially after a C-section or a hard delivery. When you're cleared to move, our postpartum workout plan takes you from your first walks to lifting, stage by stage.
How the calculator works
It uses the same formula the Solin app uses to set your daily calorie goal. It starts with the Mifflin-St Jeor equation for what a woman's body burns at rest:
10 × weight in kg + 6.25 × height in cm − 5 × age − 161
Then it multiplies that by your activity level: 1.2 for sedentary, 1.375 for lightly active, 1.55 for moderately active and 1.725 for very active. Last, it adds the breastfeeding calories for your baby's age.
Take a mom who is 32, 165 cm (5 ft 5) and 70 kg (154 lb), does light exercise 1 to 3 days a week and is nursing her 3-month-old. Her body burns about 1,939 calories a day. Add 400 for breastfeeding and her number is 2,339.
Activity is the one field you have to guess at, and it swings this mom's number by 741 calories, so pick the level closest to your usual week.
Log what you eat in seconds
Knowing your number is the easy part. Hitting it with a baby on your hip is harder. Solin Prime logs food from a photo, a barcode scan or your voice. New Prime members get 7 days free.
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