By Leia Giddens, IBCLC | Nurturing Lactation Care | Serving Macon, Sandersville, Warner Robins, Milledgeville, Lake Oconee, and all of Middle Georgia
Let me tell you about a conversation I have all the time.
A mama walks into a consultation — or calls me, or texts me at 2 a.m. from her nursing chair — and somewhere in there, she says something like, “I thought breastfeeding was supposed to help me lose weight, but I feel like I’m gaining.”
And then, almost in the same breath: “Is something wrong with me?”
No, sweet friend. Nothing is wrong with you.
But I understand the confusion. We have done a number on postpartum mothers by handing them the idea that breastfeeding equals weight loss as if it were a guarantee — a perk, a reward, a consolation prize for the sleepless nights. And when their body doesn’t cooperate with that narrative, they blame themselves.
So let’s talk about what’s actually going on.
Yes, Breastfeeding Burns Calories. But It’s Not That Simple.
Here’s what’s true: producing breast milk requires energy. Your body burns roughly 300 to 500 calories a day to make milk for your baby. Some estimates go higher, up to 500–700 calories per day for a fully breastfeeding mother. That is a real, meaningful metabolic expenditure.
And yes, research does generally show that breastfeeding mothers tend to lose postpartum weight more readily than mothers who don’t breastfeed — especially over the long term, and especially among women who had a higher pre-pregnancy BMI. A 2024 study out of Singapore found that women with a high BMI who breastfed exclusively actually lost beyond their pregnancy weight gain by twelve months, while women with a normal pre-pregnancy BMI retained more weight even when exclusively breastfeeding. (Butte et al., The Journal of Nutrition, 1998; KKH Study, 2024)
But “tends to” and “on average” are doing a lot of heavy lifting in that sentence.
Because on an individual level? The picture is a whole lot messier.
The Body You’re Living In Right Now Was Built for This
Here’s something that blows my mind every time I think about it.
That weight you gained in your hips, thighs, and rear end during pregnancy? Your body put it there on purpose. It wasn’t a mistake. It wasn’t extra. It was preparation.
From a biological standpoint, the female body begins storing fat in the gluteofemoral region — hips, thighs, and buttocks — starting at puberty, ramping up during pregnancy, specifically in anticipation of the caloric demands of lactation. Researchers call this “energy capital.” It’s an evolutionary mechanism, and it is remarkably intentional. (Lassek & Gaulin, PMC, 2021)
During lactation, the body is supposed to mobilize that stored fat as fuel for milk production. Fat is pulled preferentially from the trunk and thighs. So in a well-functioning, well-nourished system, some of that “pregnancy weight” eventually goes toward feeding your baby.
The keyword there is eventually.
Research suggests that in the first two to three months postpartum, the body is still in a kind of protective mode — it’s not aggressively mobilizing fat yet. It’s more likely to increase your appetite and conserve energy stores. From three to six months out, fat mobilization tends to pick up as feeding frequency starts to decrease. (Stuebe & Rich-Edwards, PMC, 2010)
So if you’re in the early weeks and the scale isn’t moving — or is moving in the wrong direction — that’s not your body failing you. That’s your body doing exactly what it was designed to do.
Meet Prolactin. She’s Complicated.
To understand why some breastfeeding mothers struggle with weight, you have to understand prolactin.
Prolactin is the hormone responsible for milk production. It rises dramatically during lactation and stays elevated for as long as you’re nursing. Without it, you don’t make milk. It is non-negotiable.
But prolactin has some side effects that don’t make it onto the “benefits of breastfeeding” flyers in the OB’s waiting room.
Prolactin increases appetite. Significantly, for some women. It essentially signals your body to eat more — which makes sense, because your body needs more fuel to make milk. The problem is that this appetite signal isn’t always perfectly calibrated. Some women find themselves ravenously hungry in a way that far exceeds the 300–400 extra daily calories they actually need. And if you’re eating in response to that hunger — especially under the twin stresses of sleep deprivation and a newborn — it’s entirely possible to consume more calories than lactation burns off.
Prolactin may also contribute to fat retention, particularly in the early months. Some research suggests it can suppress the body’s ability to fully metabolize fat stores while nursing is frequent and active. (Stuebe & Rich-Edwards, 2010; Harrison Healthcare, 2023)
In other words: your milk-making hormone might also be the reason the scale isn’t budging. And that is not a character flaw.
And Then There’s Sleep. (Or the Lack of It.)
I know. I know.
But we have to talk about it, because sleep deprivation has a direct, documented impact on postpartum weight — and it’s a factor that disproportionately affects breastfeeding mothers, especially in the early months.
Here’s the short version of the science: when you don’t sleep, cortisol — your primary stress hormone — stays elevated. Elevated cortisol increases ghrelin, the hormone that signals hunger, while simultaneously decreasing leptin, the hormone that signals fullness. The result is a body that is genuinely, physiologically hungrier than it should be and less capable of recognizing when it’s had enough.
High cortisol also signals the body to hold onto fat — especially in the abdominal area — as a survival response to stress. Your body does not know the difference between a famine and a newborn. It just knows you’re depleted and under duress, and it acts accordingly.
This isn’t a willpower problem. It’s a hormonal response to the most sleep-deprived period of most women’s lives.
What the Research Actually Says (and What It Doesn’t)
I want to be honest with you about the science here, because I think oversimplifying it is exactly how we got into this mess.
Researchers have been studying the relationship between breastfeeding and postpartum weight for decades. The findings are, in a word, variable. A landmark review published in The Journal of Nutrition put it plainly: changes in body weight and composition in response to lactation are “highly variable among and within diverse populations.” In most studies, rates of weight loss did not significantly differ between breastfeeding and non-breastfeeding women. (Butte, The Journal of Nutrition, 1998)
One of the most consistent findings across studies? The amount of weight gained during pregnancy is the single strongest predictor of postpartum weight retention — more than breastfeeding status, more than exercise habits, more than age or race or parity. The body has a biological drive to return to its pre-pregnancy set point, and that drive appears to operate largely independent of whether you’re nursing.
What lactation does seem to do — and this is where it gets genuinely interesting — is play a role in how that metabolic reset happens over time. There is emerging evidence for what researchers call the “reset hypothesis”: that lactation may help the body fully mobilize the insulin resistance, visceral fat accumulation, and elevated lipid levels that pregnancy creates — essentially clearing the metabolic slate. The longer a woman lactates, the more completely that reset may occur. (Stuebe & Rich-Edwards, 2010)
So breastfeeding may be less about the number on the scale right now and more about your long-term metabolic health. That’s a different story than “breastfeeding will help you lose the baby weight.” And I think it’s a more honest — and frankly more important — one.
So Why Do Some Women Lose and Others Don’t?
Honestly? All of the above, in varying combinations.
Pre-pregnancy weight and BMI. Amount of gestational weight gain. Hormone sensitivity — some women are more responsive to prolactin’s appetite-stimulating effects than others. Sleep quality and quantity. Stress levels. Thyroid function (postpartum thyroid dysfunction is more common than most people realize). Whether the weight gain during pregnancy was fat mass or fluid. Whether there was a cesarean birth and how healing is progressing. Return to movement and physical activity. Diet quality. Breastfeeding exclusivity and duration. And honestly — genetics.
Your postpartum body is not operating in a simple input/output system. It is a sophisticated, hormonally complex organism that is simultaneously healing from birth, sustaining another human life, and trying to function on fragmented sleep. The idea that it should behave predictably — or that its behavior is a reflection of your effort or your discipline — is something we need to let go of.
A Word About the Scale — and What It Misses
Here’s something worth saying: the number on the scale is not the whole story of what’s happening in your body right now.
Even when weight stays the same or increases during breastfeeding, body composition may be changing. Fat may be shifting — redistributing from your hips and thighs toward your upper body as those gluteofemoral stores get mobilized. Muscle tone may be changing. Fluid levels fluctuate. Some women find that their body shape changes noticeably even when the number doesn’t.
I’ve worked with mamas who told me their clothes fit differently at six months postpartum than they did at six weeks — without meaningful change on the scale. What was actually happening was their body’s fat redistribution catching up with their lactation.
The scale tells you one number. It does not tell you the whole truth about what your body is doing.
What This Means If You’re Struggling
If you are breastfeeding and not losing weight — or actively gaining — I want you to hear me clearly: you are not doing it wrong.
Your body is not broken. Your milk is not lesser. Your choice to breastfeed is not “not working.”
A few things that may genuinely help, within reason:
Eat enough — but eat well. Severely restricting calories while breastfeeding can backfire on both your supply and your metabolism. But the quality of what you’re eating matters. A body running on drive-through and no sleep is going to behave differently than one that’s reasonably nourished, even imperfectly. Most breastfeeding mothers need about 300–400 extra calories a day — not 700, not “eating for two.”
Give yourself a realistic timeline. The research consistently shows that the six- to twelve-month mark is when the most meaningful postpartum weight change tends to occur for breastfeeding mothers. The early weeks are not a representative sample of what’s coming.
Talk to your provider if something feels off. Postpartum thyroid issues, insulin resistance, and other metabolic conditions are real and not rare. If you’re doing everything “right” and your body is responding in confusing ways, that’s worth a conversation with your OB or midwife. You are your own best advocate.
Be gentle with yourself. This season is hard. The body you’re living in right now has done something extraordinary. It deserves kindness, not punishment.
We’re Here for the Feeding Journey — All of It
At Nurturing Lactation Care, my job is to support you in feeding your baby well — and part of that means giving you accurate information about what your body is doing and why. Breastfeeding is worth supporting regardless of what it does or doesn’t do for your waistline. The benefits to you and your baby are real and well-documented. Weight loss — if and when it comes — is a side effect, not the point.
If you’re in Middle Georgia and you have questions about breastfeeding, milk supply, or navigating the postpartum season in general, we’d love to hear from you. We serve families across the region — Macon, Warner Robins, Milledgeville, Sandersville, the Lake Oconee area including Greensboro and Eatonton, and the rural communities in between — through in-home visits, office consultations at our location on Vineville Avenue in Macon, and telehealth appointments for families who prefer the convenience of virtual care.
You can reach us at (478) 288-8784 by call or text, or book online at nurturinglc.com.
Your body is doing its best. Let us help you do the same.
References:
Butte, N.F. (1998). Body Composition Changes during Lactation Are Highly Variable among Women. The Journal of Nutrition, 128(2), 381S–385S.
KK Women’s and Children’s Hospital. (2024). Exclusive breastfeeding leads to greater weight loss in women with high body mass index.
La Leche League International. (2024). Weight loss while breastfeeding. Retrieved from llli.org.
Stuebe, A.M., & Rich-Edwards, J.W. (2009). The Reset Hypothesis: Lactation and Maternal Metabolism. American Journal of Perinatology, 26(1), 81–88. PMC3006166.
Butte, N.F., Garza, C., Stuff, J.E., et al. (1989). Postpartum changes in maternal weight and body fat depots in lactating vs nonlactating women. American Journal of Clinical Nutrition, 49(2), 259–265.
Lassek, W.D., & Gaulin, S.J.C. (2021). Gestational potential space hypothesis: Evolutionary explanation of human females body fat redistribution. PMC8653625.
Leia Giddens is an International Board Certified Lactation Consultant (IBCLC) and the founder of Nurturing Lactation Care, serving families throughout Middle Georgia including Macon, Sandersville, Warner Robins, Milledgeville, the Lake Oconee area, and surrounding communities. Rebecca Foley, RN, IBCLC, also sees patients at Nurturing Lactation Care.