Does Breastfeeding Help to Lose Baby Weight?

Something that tends to be on many women’s minds after having a baby is “How do I lose the baby weight?” I want to preface this post with the caveat that I do not think that it necessarily SHOULD be a topic on our minds at that time, but it is very common for it to be something we think about. It certainly rolled around in the back of my own mind after having my son last year! Breastfeeding is often talked about as one thing that can really help us to lose the baby weight. But is that really true?

Research on Breastfeeding

It is important to realize that studying breastfeeding is incredibly difficult to do. It is a very individual experience in many ways. How exclusively a woman breastfeeds, and for how long, are affected by a multitude of factors. Even if a woman meant to breastfeed exclusively for a certain amount of time, things may happen that prevent that. Since every woman’s experience is so different, it’s difficult to categorize people into groups in order to study them well.

There are also a TON of other confounding variables that come into play. It’s hard to isolate breastfeeding as ONE thing that’s different in a mother’s life, making it difficult to say conclusively that it’s responsible for anything. Mothers who breastfeed may also be more or less likely to do other things in relation to their parenting and overall lifestyle choices, so isolating the breastfeeding isn’t really possible. Additionally, the research is observational, not experimental. This makes sense, since you can’t very well sort pregnant women into groups and assign them to either breastfeed or formula feed (or any combination in between), as you would in an experiment. That’s neither practical OR ethical!

That said, there is research out there on this, along with the baseline knowledge that breastfeeding burns calories. It takes energy to produce and distribute the milk. So, in theory, if a woman was to eat the exact same amount that she did before pregnancy, and she’s now burning more energy by breastfeeding, then yes, she would be in a calorie deficit and should lose weight. But is life ever that simple (especially for a new mom)?

An overview of what we know

When looking at the research on breastfeeding and weight loss, the term they use is actually Postpartum Weight Retention (PPWR). It’s a measure of how much Gestational Weight Gain (GWG) is kept on after the baby comes. Studies look to see if breastfeeding (or any other factor) is associated with a decrease in PPWR (meaning less weight is retained).

Studies are conflicting. Some show that breastfeeding is associated with reduced PPWR.1–3 Other studies don’t show an association.4 (Remember, correlation does not equal causation. Just because some studies show that women who breastfeed have less weight retention, it doesn’t necessarily mean that the breastfeeding caused the weight loss.) Even studies that compile the data from a bunch of other studies can’t find a consistent answer. Remember what I wrote above: studying breastfeeding is pretty darn hard.

A few things do seem to be related to PPWR though:

1 – How much weight was gained in pregnancy (GWG). It makes sense that the more weight a woman gains, the more weight will have to be lost to return to the pre-pregnancy weight. When we gain a lot of weight, it is understandably harder to lose all of it, and thus these women with higher GWG tend to have higher PPWR.2,3,5–8

2 – Lifestyle plays a big role. I don’t think anyone should be surprised by this. A woman who has healthy lifestyle behaviors is able to reduce her PPWR better than someone who does not have healthy habits.9,10 Specifically, dietary interventions have a bigger impact than exercise interventions. Fat loss happens in the kitchen!

3 – Higher pre-pregnancy BMIs is associated with higher PPWR, as well as a lower likelihood of breastfeeding (or having less success in initiating breastfeeding).3,5,6,11 It’s possible that the breastfeeding difficulties this population experiences could be related to the increased PPWR.

When we boil this down, it actually ends up being a pretty common sense answer

Breastfeeding is wonderful, but it’s not magic. Weight loss is weight loss. Breastfeeding can certainly help us to lose some of the baby weight because it burns more calories than not breastfeeding. However, healthy behaviors are still king. Just like the saying “You can’t out-exercise a bad diet,” so too can you not out-breastfeed a bad diet. If you’re eating more than enough to make up for the calories you’re burning while breastfeeding, you won’t see the weight loss you’re after.[bctt tweet=”Just like “You can’t out-exercise a bad diet,” so too can you not out-breastfeed a bad diet.” username=”raisingnutritn”]

Eating healthfully, and eating the right amount for your current situation, is something that ideally starts before we get to the breastfeeding stage. Women who begin their pregnancies at a normal BMI have fewer pregnancy-related complications, and tend to have less PPWR than women who enter pregnancy overweight or obese. While pregnant, women who gain the appropriate amount of weight have less PPWR than do women who gain more weight. After pregnancy, women who eat well and exercise are more likely to reduce their PPWR than are those who don’t engage in those healthy behaviors.

Breastfeeding helps burn calories, yes. But it’s not the end-all and be-all of the situation. If we want to lose weight, regardless of when in our lives we’re looking to do it, we need to address our overall lifestyle, habits, skills, and behaviors.

Any mamas out there want to share their experience? As always, I’d love to hear from you. And please share this post with the other moms you know!


  1. He X, Zhu M, Hu C, et al. Breast-feeding and postpartum weight retention: a systematic review and meta-analysis. Public Health Nutr. 2015;18(18):3308-3316. doi:10.1017/S1368980015000828.
  2. Baker JL, Gamborg M, Heitmann BL, Lissner L, S??rensen TIA, Rasmussen KM. Breastfeeding reduces postpartum weight retention. Am J Clin Nutr. 2008;88(6):1543-1551. doi:10.3945/ajcn.2008.26379.
  3. Sámano R, Martínez-Rojano H, Godínez Martínez E, et al. Effects of breastfeeding on weight loss and recovery of pregestational weight in adolescent and adult mothers. Food Nutr Bull. 2013;34(2):123-130. Accessed June 6, 2016.
  4. Neville CE, McKinley MC, Holmes VA, Spence D, Woodside J V. The relationship between breastfeeding and postpartum weight change–a systematic review and critical evaluation. Int J Obes (Lond). 2014;38(4):577-590. doi:10.1038/ijo.2013.132.
  5. Vinter CA, Jensen DM, Ovesen P, et al. Postpartum weight retention and breastfeeding among obese women from the randomized controlled Lifestyle in Pregnancy (LiP) trial. Acta Obstet Gynecol Scand. 2014;93(8):794-801. doi:10.1111/aogs.12429.
  6. Ellen A Nohr, Michael Vaeth, Jennifer L Baker, Thorkild IA Sørensen, Jorn Olsen and KMR. Combined associations of prepregnancy body mass index and gestational weight gain with the outcome of pregnancy 1 – 3. Am J Clin Nutr. 2008;342:10-15. doi:10.3945/ajcn.2008.26939.Combined.
  7. Nehring I, Schmoll S, Beyerlein A, Hauner H, Von Kries R. Gestational weight gain and long-term postpartum weight retention: A meta-analysis. Am J Clin Nutr. 2011;94(5):1225-1231. doi:10.3945/ajcn.111.015289.
  8. Widen EM, Whyatt RM, Hoepner LA, et al. Excessive gestational weight gain is associated with long-term body fat and weight retention at 7 y postpartum in African American and Dominican mothers with underweight, normal, and overweight prepregnancy BMI. Am J Clin Nutr. 2015;102(6):1460-1467. doi:10.3945/ajcn.115.116939.
  9. Neville CE, McKinley MC, Holmes VA, Spence D, Woodside J V. The effectiveness of weight management interventions in breastfeeding women–a systematic review and critical evaluation. Birth. 2014;41(3):223-236. doi:10.1111/birt.12111.
  10. Boghossian NS, Yeung EH, Lipsky LM, Poon AK, Albert PS. Dietary patterns in association with postpartum weight retention. Am J Clin Nutr. 2013;97(6):1338-1345. doi:10.3945/ajcn.112.048702.
  11. Martin J, MacDonald-Wicks L, Hure A, Smith R, Collins CE. Reducing postpartum weight retention and improving breastfeeding outcomes in overweight women: a pilot randomised controlled trial. Nutrients. 2015;7(3):1464-1479. doi:10.3390/nu7031464.

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