How to Lose Weight While Breastfeeding, by Your Baby's Age
It depends on how old your baby is. Under 7 months, eat all the calories you and your milk need: that alone takes weight off slowly. From 7 months, you can aim for up to a pound a week, as long as you eat at least 1,800 calories a day. For many moms, that means moving more, not eating less. Check with your doctor before you change how you eat or exercise.
How fast can you lose weight while breastfeeding?
Slower than you'd like. We're going for strong, not starving.
Under 7 months: eat the number our breastfeeding calorie calculator gives you. It already takes about 140 calories a day from the fat you stored in pregnancy, which is about 1.4 lb a month. Cutting more on top of it is cutting twice.
From 7 months: the calculator's number only holds your weight steady, so to lose weight you eat less than it. Aim for up to a pound a week, the goal the Academy of Nutrition and Dietetics and La Leche League give. MedlinePlus says up to a pound and a half shouldn't affect your supply. We'd stick with the pound.
That pace has been tested. In a trial of 40 overweight, breastfeeding-only moms, those who ate 500 calories a day less and exercised 4 days a week, starting 4 weeks after birth, lost 4.8 kg (10.6 lb) in 10 weeks, against 0.8 kg for the others. Their babies grew just the same: 1,925 g against 1,861 g.
Can you lose 10 pounds in a month? That's more than 2 lb a week, faster than any of these sources call safe. Twenty pounds takes about 20 weeks at a pound a week, and longer if your baby is under 7 months.
How many calories can you cut from 7 months?
In the Solin app, a pound a week means eating 500 calories a day under the number from our calculator. The catch: don't go under 1,800 a day. The Academy says eating less than that may lower your milk. For many moms, those two rules don't fit together.
Take a 30-year-old mom who's 5 ft 5 in. If she's sedentary and weighs 150 lb, her daily calories are 2,062, so she has only 262 calories to cut before she hits 1,800. That's about half a pound a week. Even at 190 lb, she has 479. Still short of 500.
If she moves a little more, to light exercise 1 to 3 days a week, her daily calories at 150 lb rise to 2,307, and she has 507 calories of room. Now she can cut the full 500. Moving more is what made the room, not eating less.
Find your own number with the calculator and subtract 1,800 from it. Under 500? Go slower or move more.
Does exercise affect your milk supply?
No. In a study of 33 breastfeeding-only moms, half did 45 minutes of aerobic exercise 5 days a week, starting 6 to 8 weeks after birth. After 12 weeks, the two groups had the same amount of milk, made of the same things, and their babies gained the same. La Leche League adds that exercise doesn't change its taste either.
The moms who exercised also ate more, 2,497 calories a day against 2,168, and didn't lose more weight. Workouts won't take the weight off by themselves. They do help you lose fat instead of muscle.
Feed your baby or pump before you work out, so you're comfortable. For when to start lifting and what to do first, see our postpartum workout plan.
What should you eat, and which diets should you skip?
Eat protein at every meal and think 80/20: real food most of the time, with room for the things you love. Our high-protein meal plan has a week of meals to start from.
Lower-carb can work: La Leche League thinks it's safe as long as you still eat plenty of fruit, vegetables and protein, and enough calories overall. Two ways of eating are worth skipping while you breastfeed:
- Strict keto. Some case studies link very low-carb or strict keto diets while breastfeeding to lactational ketoacidosis, a rare medical emergency. The moms in them recovered, but it's not worth the risk.
- Intermittent fasting. La Leche League doesn't recommend eating only in a set window while you breastfeed: there isn't enough information yet to know whether it's safe. Smaller meals spread over the day work better.
How do you know your milk supply is OK?
Watch your baby, not the scale. The American Academy of Pediatrics says the best clues are how fast your baby gains weight, how many wet and dirty diapers there are, and how satisfied your baby seems after feeding. Your baby's checkups will track the weight.
If those change while you're losing weight, eat more and slow down. Then call your doctor or a lactation consultant.
Move more, so you can eat enough
Solin creators run programs built for after birth. Every challenge comes with a community of moms going through the same weeks, and there's a 30-day money-back guarantee. Check with your doctor, then pick one that fits where you are.
See postpartum programs