Are you not losing weight breastfeeding after giving birth? We review the research to determine does breastfeeding cause weight loss or weight gain?
Over the past few months, I’ve had countless of other new moms say to me, “I’m breastfeeding! Why aren’t I losing weight?” Real talk ladies, doesn’t it feel like we’ve paid our dues? We spend 9 months undergoing extreme/often uncomfortable changes to our bodies and then we go through the physically demanding act of childbirth. Once we get to breastfeeding, shouldn’t we get a free pass?
Well, you all know that my breastfeeding journey has been nothing short of hell, and I know I’m not alone. The one “benefit” that I’ve heard keeps so many going is its ability to help you shed that baby weight faster. I mean, everyone and their grandma reassures us that breastfeeding makes the fat “melt away”. Even a recent tabloid I picked up suggested that Kate Middleton breastfed herself skinny. It’s no surprise we all believe that the complex postpartum weight loss journey can be boiled down to the magic of one single act.
Like all physical acts, breastfeeding requires energy, which translates into burning calories. On average, you burn 20 calories to create 1 ounce of breast milk. So to put this into my own personal terms. I’m producing, on average, 1300-1400 ml of milk a day. That’s about 45 oz, or 900 extra calories required. Now, I’m eating like a maniac in response to those increased needs, but if you didn’t you could quickly lose weight. And yes, some women really do lose weight through breastfeeding! However, we’re usually only told half of the story, and though your friend may be losing weight breastfeeding, it might not work that way for you.
Let’s get into it.
Does Breastfeeding Cause Weight Loss? Weighing the Evidence
Alright, let’s start with my favourite: some good, old-fashioned, reliable evidence. These studies (and here) found that breastfeeding did not cause weight loss after birth. Rather, their findings suggested that other factors like gestational weight gain and lifestyle behaviours such as sleep and diet played a bigger role- but more on that a bit later.
Now is the part you’re not going to like. Another study found that a large proportion of the moms who breastfed gained about 1 kg, compared to moms who didn’t. WHAT THE WHAT?! Finally, a comprehensive review of the most up-to-date evidence found there wasn’t sufficient evidence to suggest that breastfeeding causes weight loss, however they really emphasized the need for more robust and controlled studies before making any strong statements.
It’s definitely true that women tend to lose weight postpartum, however, the weight loss trajectory is not as straightforward as we think. In fact, it’s common to lose lots of weight in the initial 2-3 weeks, and then hit a baby weight plateau, resulting in many women with question marks above their heads. I was doing so well and losing weight steadily? Â What happened?
Well, let’s explore some reasons why you may not be losing weight breastfeeding.
Pregnancy Diet and Gestational Weight Gain
Let’s start from the beginning of the story: the pregnancy stage. Many people confuse “eating for two” as “eating twice as much”, treating pregnancy as an opportunity to eat whatever they want. Having gone through it myself, I don’t blame ya! I definitely had my fair share of cravings, and I cherished Every. Single. Bite. But I’ve also seen so many people gasp in shock when they realize exactly how many extra calories are recommended during pregnancy.
Are you ready for it? (Hint: it’s probably much less than you’re guessing).
To support their baby’s development, women just need to have an extra 350 calories in their 2nd trimester and 450 extra calories in their 3rd trimester. This translates into a small sandwich and a glass of milk. Health Canada refers to this as “just a little more food”. So all those TV shows and movies where you see a pregnant women eating 2 slices of chocolate cake, washing it down with a milkshake and then miraculously popping back into a tiny shape after giving birth? YAH, that’s bullshit.
Researchers did a huge meta-analysis of this and found that women who had gestational weight gain beyond the recommendations retained an additional seven pounds after three years postpartum. Then an additional ten pounds fifteen years later. Another study found similar results and concluded that keeping weight gain to a healthy amount by eating according to your needs may help with postpartum weight retention. Of course, what you definitely should not do is diet (read about the dangers of dieting here), but rather, focus on listening to your body for those subtle increases in hunger that come with your enhanced needs.
Prolactin, Stress Hormones and Weight Loss During Breastfeeding
photo credit: https://toolstotal.com/
As with many things relating to weight, hormones play a big role. In this case, it’s prolactin, a hormone that is increasingly known as the “fat-storing hormone”. Prolactin is raised during pregnancy, and is secreted to stimulate milk production during breastfeeding. In other words, it helps mom make milk for the baby. There’s early research indicating that it may also reduce fat metabolism in the mom, hence why the weight seems like it just won’t come off. Additionally, experts say it may increase your hunger levels – so if you ever find yourself ravenous while breastfeeding (I know I am), this could be why! As this is very early research (like, university-thesis level early), there’s still correlations that have yet to be proven, but it’s definitely an interesting start. Countless doctors and healthcare practitioners hypothesize that our bodies undergo a hormonal and metabolic adaptation to hold onto fat as “insurance” for nourishing the baby. I’m excited to see future research on this potential hormonal activity in fat metabolism.
Though there are no human studies, there are some controlled trials that look at prolactin and fat stores in animals. This study on hamsters found those with reduced prolactin secretion levels also had reduced fat stores by 25-49%. So is a decrease in prolactin associated with a decrease in fat, and an increase in prolactin associated with an increase in fat? Only time, and more controlled and wide-scale human studies, can tell.
Stress and Cortisol
Oh lordy, motherhood can be stressful. Don’t have to say that twice, right? We all know chronic states of high stress is harsh on our bodies, from increasing our risk of chronic diseases to psychological impacts like depression. For some, stress can also shift our body weight above where it would otherwise naturally happily be. Researchers found that overall life stress, particularly maternal stress, is a key indicator for weight retention. Another research study did a little backtracking and found a similar connection with anxiety during early pregnancy and postpartum weight retention.
So how does stress relate to postpartum weight? In response to stress, our bodies release a hormone called cortisol, which can be healthy in moderate amounts. However, when we’re feeling super stressed for extended periods of time, our bodies can go into overdrive cortisol production, and an excess amount of cortisol is shown to be related to weight retention in the first 12 months postpartum. Beyond stress, postpartum depression is a condition that can affect many and is also associated with weight retention.
If you’re living with postpartum depression, weight should be the very last of your worries – seek some professional help and know that you’re not alone! This clearly emphasizes the need for a more holistic approach to health in postpartum women – from what we eat, to how we manage our stress levels. It’s important for us to focus on these factors rather and remember to look after ourselves as a whole. The weight will be what it needs to be.
Adrenal fatigue and weight loss – a real diagnosis?
Some doctors have provided clinical perspectives that support the case of “adrenal fatigue”, which apparently shows itself through a collection of nonspecific symptoms such as body aches, lightheadedness, low blood pressure, and of course, fatigue. The theory here is that our adrenal glands, which are responsible for cortisol, can become, well, fatigued over a long period of prolonged stress. These glands end up producing less cortisol, and can’t keep up with the stress demands of the body. This can potentially lead to weight gain, fatigue and the aforementioned symptoms.
So far, The Endocrine Society, made up of over 1400 endocrinologists specializing in hormonal health, released an official statement announcing “adrenal fatigue is NOT a real medical condition, and there are no scientific facts to support the theory.” They emphasize treating their fatigued symptoms through other more evidence-based means. I’m personally super excited to see how future research may support (or reject, who knows?) this super trendy diagnosis!
Sleep, Diet and Postpartum Weight Loss
So what do we know for sure? Well, we know that motherhood is hard AF. There are days when taking even 10-minutes for yourself to have a shower can be a challenge. Sleep has mostly been replaced by coffee (my BFF for life) and you just have to get comfortable with eating granola bars for most meals. Unfortunately, short sleep duration, something that so many of us experience as new parents, is shown to be connected to weight gain or retention. Another lifestyle factor is your diet related to the increased hunger you may experience while breastfeeding, as our bodies need more calories to meet this demand. Similar to a pregnancy diet, our energy needs are increased, but often, we tend to ignore the subtle hunger cues, and overeat. It’s also common to let ourselves get so hungry we can’t help but go crazy the moment we do eat. Either scenario may have you eating beyond your modest enhanced calorie needs during breastfeeding. So in addition to three balanced meals, it’s important that you always plan out a few healthy snacks to avoid letting yourself get too ravenous in between meals.
So: Does Breastfeeding Cause Weight Loss or Weight Gain?
I hope that I gave you enough information today to be confident and know that weight loss isn’t inevitable in the months postpartum. Also you’re not doing anything “wrong” if you’re breastfeeding and not losing weight. Breastfeeding is amazingly difficult work. If you’ve chosen to take that on for your baby, just know that it’s a selfless act and like pregnancy, is yet another phase for your bad ass body. Whether or not you lose weight should not be the reason you breastfeed or ween. Just trust that your body is doing exactly what it needs to do to nourish your baby best.
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If you liked this post, you may like:
Breastfeeding vs Formula or Bottle Feeding and The Risk of Weight Gain
Colic in Babies and Dairy | Should Breastfeeding Moms Go Dairy Free
Is it Safe to Breastfeed on a Keto Diet and How Does it Affect Breast Milk
How to Increase Breast Milk Supply
What’s your experience with postpartum weight loss?
Did you lose weight breastfeeding? Did you gain weight breastfeeding?
What are your best new-mom self-care tips?
RD2B Trista Chan
Updated on December 8th, 2021
Abbey Sharp is a Registered Dietitian (RD), regulated by the Ontario College of Dietitians. She is a mom, YouTuber, Blogger, award winning cookbook author, media coach specializing in food and nutrition influencers, and a frequent contributor to national publications like Healthline and on national broadcast TV shows.
Katie V says
Thank you for such an amazing article! exactly what I was looking for! I’m 9 months PP and have 10 lbs to go. I gain a lot during my pregnancies (this time 40lbs total) and after giving birth I had 27 lbs to lose of my own. The only tried and true method I have found is calorie counting. I found a breastfeeding calorie calculator online to help me do the math and so far I have lost 17 lbs in 6 months. It is tedious and seems a bit slow but its the only way to go for me since I don’t want to risk losing my milk. I hope this helps someone, because it doesn’t feel good to think weight loss is hopeless, we can do it! 🙂
Health n wellness says
Thanks for this wonderful and knowledgeable post, looking good thanks for sharing with us.
CONTROL YOUR BLOOD PRESSURE WITH YOGA
Abbey Sharp says
I have a 5 month old and he started sleeping through the night at 3 months so that helped with my exhaustion levels. I also exclusively pump milk (breastfeeding was a damned struggle and my husband and I were infertile for a long time so it was emotionally important for us that my husband get to feed our baby as well). Prior to my pregnancy (which I did via IVF) I had lost 28kg (55lb). I taught myself to run and I was doing weight training on a regular basis. I dropped to a size 12 (from size 16) for the first time in my life since I was 15. During all our infertility testing my Doc also found out I had thyroid disease, so I got that sorted with meds. That all said, 5mo post partum, I have not lost a shred of weight (except that which was baby, placenta and amniotic fluid of course) and Ive been wearing all my old pre-weightloss clothes which feels very discouraging. Ive been stuck at the same miserable 84kg since day 2 PP. At the beginning, I was gentle on myself – just trying to survive through the exhaustion and maintain my milk supply and being a new mom and enjoying my son. My milk supply was impressive to say the least. I currently only pump now during day time hours and I still produce plenty, though we add formula occaisionally. When my son started sleeping through the night I started back on MyFitnessPal and gave myself 2000 cal (3 meals, 2 snacks). I drink huge amounts of water. Im eating 90% clean. Im back into swimming and treadmill hiking, and my Womens Physio (I call her the vagina physio), has been helping me get my pelvic muscles back into shape for running.
All this, and I have not lost ANY weight! Still stuck at the same damned 84kg. Its frustrating to say the least. Meanwhile, all my other breastfeeding Mom friends who’ve had babies – their PP weight has just fallen off! So frustrating. I guess to me it makes sense that some women retain fat for milk making, but during my pre-natal class they laid on thick the amazing weightloss that occurs in breastfeeding (and told us no downsides), so now I feel lied to and wish they were at least more intellectually honest in their info. I wonder if its also genes. All women in my family are heavily hourglass shaped. My Doc just recently got me to do a blood test for him to see how my hormones are doing so I’ll wait and see how that goes. Otherwise, perhaps I should just see what happens when I wean at 11 months…
Jennifer Ross says
I am a dietitian as well, with a background in many aspects of dietetics. Weight management is a significant area of professional expertise for me.
First, thank you for writing this! It’s an important and under-discussed topic.
With both of my pregnancies I lost the weight fairly quickly and (yes, I know we’re not at all defined by our weights, and I completely agree) I was delighted. I’m not slim and small, and will probably never regularly have a BMI below 25 again in my lifetime, so to get down to a place I felt comfortable and in good health was great. But then…I packed on 10 pounds FAST 10 months to 1.5 years after the babies were born. Like, FAST. So fast there was nothing I could do about it before it happened. So for whatever reason, my body does this. I have some hypotheses about what has caused it.
I think sleep, stress, some very stressful travel I needed to do both professionally and personally, and the baby cutting back on quantity of breastmilk were factors. Some medication docs are so quick to dole out but don’t always fully comprehend or appreciate the side effect profiles of may have been another factor.
I am still breastfeeding my second child, but with my first I was finally able to lose some of the weight I regained. But it happened once I stopped breastfeeding. I also upped my strength training, which seemed to help. I hope I can take this weight off, not for appearance but because I feel genuinely unwell carrying around this extra weight.
Take care and thanks again for writing.
Abbey Sharp says
Hey Jennifer, thanks so much for your comment.
such A good read, but I’m starting to think I am a Golden Goose. Before pregnancy I had no problems keeping weight off. But now I haven’t lost a pound since returning home from the hospital. I’ve been EBF for the last year and haven’t lost a pound. I cut out sugar, alcohol, I eat six small meals a day all on top of 2 hours of cardio and still can’t lose a lb. I’ve talked to my doctor and there seems to be nothing wrong with me. I’m starting to feel like breastfeeding is the reason I can’t lose a pound
Bethany Rutledge says
Love this post. I definitely felt strange hormonally while BF–in some ways good and some ways bad.
Abbey Sharp says
Julie Wunder says
Such an interesting read! I actually feel bad sharing my story because it is so different from others. I got really really sick after I delivered the twins and could not keep ANY FOOD DOWN. I survived on frozen fruit bars and ended up having to drink ensure to get any calories. The doctors still don’t know what happened but I ended up losing all of my twin pregnancy weight within WEEKS. It was SO unhealthy. Luckily whatever it was cleared within a month and I started to eat again… otherwise, I’m pretty sure they would have put me in the hospital!
Abbey Sharp says
Oh gosh well I’m so glad you recovered okay!
Yes yes yes! This is me!!! I am 9 months PP exclusively pumping still and still have 20lbs to go to hit pre-pregnancy weight (and pre-pregnancy I also wanted to lose another 10 vanity pounds). This is so encouraging. I’ve said all along my body is just so dang sensitive to hormonal changes and I’ve seen it first hand in pregnancy. I expected to give up my body during pregnancy but nobody really warned me that my body would still not be my own while I was pumping afterwards. It’s a tough reality check. I’m so hoping after quitting pumping soon that the weight falls off. Lord knows I’ve been trying. I’m just about ready to murder my scale.
Abbey Sharp says
stop weighing yourself! your body needs time!
Me too! I’m 4 months pp and weigh the same as I did at 4 weeks pp- with 30+ pounds to lose! It will not budge. Ugh.
Same here! Right down to the lbs! I’m 10 months post partum. Every time I lose a couple of pounds my body starts craving to put them back on again. Feels like a losing battle. I do feel very hormonal and am hoping weight will drop off when I stop bf but still have 8 more months of this :-/
So how do we lose the weight? I’ve got about 10 pounds from this pregnancy and 15 from my last to lose. I lost all the 65 from my first pregnancy with twins and pumped/ breastfed for a year but gained 15 at about 8 months postpartum that I never lost. This pregnancy I’ve lost 35 of the 45 and I’m 8 weeks postpartum.
Abbey Sharp says
Sadly it’s something we don’t have an easy answer for. Speaking with a dietitian may help to provide you with some healthy lifestyle tips.
I’m one year PP and still struggling so much with losing the baby weight. I am still EBF and am trying to let me daughter tell me when she’s ready to be done but I still have about 20 lbs to loose. I track meals with weight watchers and I just started working out with a personal trainer but am not seeing the scale move!
Thank you so much Abbey for a informative article.
Abbey Sharp says
you’re so welcome!
J René says
Great article Abbey! Fellow RD here as well and I also assumed breastfeeding would help with weight loss, especially when combined with healthy foods and exercise. My experience is similar to another commenter above – the last 8-10 pounds are still lingering while I nurse, despite gaining less weight in this pregnancy. I wasn’t able to breastfeed my son and the weight was already gone by this point and I had gained much more! I’m curious to see what new research comes out about the hormones – I think that’s definitely a big player, at least in my case! Thanks again for the great article.
Abbey Sharp says
Definitely. Hopefully we get some more research soon to understand this a bit better. Thanks for your comment 🙂
I lost weight 25lbs while pregnant. Now 9 months postpartum and I’ve gained 20lbs from where I originally started when i got pregnant. I’m hoping once i ween i can loose all the weight. But who knows PCOS screws alot of things up.
Abbey Sharp says
Hi Ashley, sounds very frustrating. I can relate that PCOS can be really confusing and misunderstood. Hopefully more research on PCOS can give us some better answers. Thanks for your comment
Great article! This was such a good read for me as I thought I was some sort of freak for not losing weight after having my first baby despite my consistent pumping every 2-4 hours (I had a hard time breast feeding but was determined to feed breast milk). I’ve always been very petite, never weighed more than about 120 and am 5’3 and after my first baby I weight around 165! I was so depressed about that on top of having pretty sever PPD. I did eat a lot more than normal as I tend to go for periods of time with literally not eating at all due to lifelong severe anxiety and depressive disorders and breastfeeding made me soooo hungry the first couple of months. Once I stopped pumping at around 6 months, the weight seemed to just disappear… and keep disappearing until I was pretty badly underweight. Fast forward 3 years, I became pregnant with my son (who is now 7 weeks old) I was only 96 pounds and didnt get periods anymore due to being underweight so I had no idea I was pregnant until almost 12 weeks once I began having daily morning sickness. This was a huge shock since I supposedly couldn’t even get pregnant the first time (let alone a second time) after having a ruptured ectopic pregnancy and losing one of my tubes and was told I would have needed IVF but still managed to get pregnant naturally, (Amazing how our bodies can adapt). Anyway, I am currently breast feeding my son (as well as supplementing). My son was almost a month premature and lost a bit too much of his birth weight and then wasn’t gaining fast enough, and was jaundiced so we had to ensure he was getting enough nutrition. He is doing well now and I am really hoping to work back up to exclusively breastfeeding (therefore building my supply up to speed), as long as our pediatrician says he has caught up enough to no longer need the back up supplementation. I can’t really tell yet how my weight is being affected though, I don’t feel like I’ve either lost or gained a significant amount. I definitely have gained weight overall since becoming pregnant and can’t get my old jeans over my thighs/hips yet.. but now I’m probably a more normal, healthier weight than pre-pregnancy. I’m just so used to being very tiny that I guess I just *feel* weird. I suppose I’ll just have to wait and see how things go this time. It’s very nice to have this information and see that not all woman drop all the weight breastfeeding and I’m not that abnormal. Thanks for writing this, super informative! (Sorry for such a crazy long comment and thanks for reading my rambling!)
Abbey Sharp says
Hi Avra thanks for sharing your story!
I am now 10 mo pp and still pumping so my weight hasn’t really changed but I’m interested to see what happens when I stop in two months. Very interesting you quickly lost the weight (and then some!!) – do you think that was all just hormone change or did you find yourself eating a lot less food once you stopped breastfeeding?
Congrats! I think the weight loss initially started from hormonal chances because literally within a couple of days within stopping pumping I started getting periods again . All the weight I continued to lose beyond my healthy original weight, I think was all from not eating caused by my depression and anxiety. I just wasn’t very healthy because of that and didn’t look that good because I was actually too skinny. Good luck to you with achieving your goals on this journey!