Oops! Breastfeeding INCREASES the risk of childhood obesity

The size of stomach of children with overweight.

Most of the evidence for the purported benefits of breastfeeding for term infants is weak, conflicting and riddled with confounders … not to mention distorted by white hat bias. Time and again, rigorous studies have failed to confirm the breathless pronouncements of lactivists. Now a new study shows that far from preventing childhood obesity, breastfeeding seems to increase it.

Yet another claim of lactivists is demonstrated to be false.

The title of the study published JAMA Pediatrics is a mouthful: Effects of Promoting Long-term, Exclusive Breastfeeding on Adolescent Adiposity, Blood Pressure, and Growth Trajectories A Secondary Analysis of a Randomized Clinical Trial.

This analysis found:

A randomized intervention that increased the duration and exclusivity of breastfeeding was not associated with lowered adolescent obesity risk or BP. On the contrary, the prevalence of overweight/obesity was higher in the intervention arm…

It is a secondary analysis of data derived from the PROBIT studies, long considered some of the gold standard studies in breastfeeding research.

The Promotion of Breastfeeding Intervention Trial (PROBIT) was designed to overcome limitations inherent in observational studies of the long-term effects of breastfeeding on child outcomes including adiposity and blood pressure. We cluster-randomized 17 046 children from 31 clinics, born between 1996 and 1997, to either a control arm or breastfeeding promotion intervention (based on the World Health Organization and United Nations Children’s Fund Baby-Friendly Hospital Initiative).

The initial data from the studies found that the only solid evidence of benefit from breastfeeding was limited to a slightly reduced incidence colds, and a slightly reduced incidence of episodes of diarrheal illness across the entire population of term infants in the first year. But lead researcher Dr. Michael Kramer believed that the data suggested that breastfeeding might have a beneficial effect on IQ and obesity.

Subsequent data from his studies and others has caused him to change his mind about breastfeeding and obesity. The data is consistent with Kramer’s previous observations:

We previously reported no evidence of a protective effect of the breastfeeding intervention on adiposity or BP at 6.5 and 11.5 years.

So one of the original proponents of the claim that breastfeeding prevents obesity found out years ago that it does not and is now emphatic in denying a connection:

An intervention that achieved substantially greater duration and exclusivity of breastfeeding in Belarus did not prevent over-weight or obesity or lower BP levels at age 16 years, despite differences in growth rates between the trial arms at various ages. On the contrary, overweight and obesity were more prevalent in the breastfeeding promotion intervention arm. While there are many reasons for promoting breastfeeding duration and exclusivity, our trial does not indicate that breastfeeding prevents obesity or lowers BP in childhood or adolescence.

Dr. Kramer does nevertheless engage in a bit of white hat bias. Had his data shown a decrease in risk of obesity in the group that was breastfed longer he almost certainly would have claimed that breastfeeding prevents obesity. But in keeping with the white hat bias of all breastfeeding researchers (that breastfeeding must be better than not breastfeeding) he does not follow where the data leads him: the possibility that breastfeeding causes obesity. I point this out not because I believe that the evidence shows that breastfeeding causes obesity (although it might), but because it highlights the profound bias in favor of breastfeeding within the scientific community.

Kramer himself has long been far more sober about the purported benefits of breastfeeding than many other lactivists.

In a 2016 interview on Canadian radio, Kramer was emphatic that breastfeeding does NOT prevent obesity, does NOT prevent allergies, and does NOT prevent asthma. When asked why lactivist organizations continue to insist on benefits that have been shown not to exist, he explained that these organizations rely upon preliminary data and simply refuse to accept anything that contradicts it. He was quite blunt that about the fact that lactivist organizations won’t accept scientific evidence that doesn’t comport with what they believe and he worries that their insistence of exaggerating benefits will undermine women’s trust in healthcare providers.

In the interview Kramer was refreshingly honest in acknowledging that public health officials underestimate the difficulties of breastfeeding. When asked whether the public health community can present the actual scientific evidence instead of the selected evidence that it prefers to present, he ruefully explained that “no one likes shades of gray,” preferring black and white pronouncements instead.

Breastmilk is food not magic.

Sadly breastmilk has been turned from food into manipulation. Lactivists and their organizations, especially the Baby Friendly Hospital Initiative, have made the harassment, inconveniencing and embarrassment of women a cornerstone of their efforts to promote breastfeeding. As Kramer himself acknowledges, most of their claims are empirically false and their efforts are beginning to backfire.

Michael Kramer, the person whose research led to the claim that breastfeeding reduces the risk of obesity, has officially withdrawn that claim. Does anyone want to bet against me when I predict that lactivist organizations will ignore the latest evidence and refuse to remove the claim from their websites and educational materials?

Lactivist organizations are certain that breast is best even when the evidence not only doesn’t support their claims but actually contradicts them. Regrettably, they are so sure of their own righteousness that they have become entirely unmoored from scientific evidence. Mothers and babies are placed at serious risk, under significant pressure, and with deadly consequences as a result.

  • Have you seen this Vox piece yet:
    https://goo.gl/owpzDM

    • Roadstergal

      Wow. That started off encouragingly – describing proactive steps taken at hospitals to manage potential complications before they become lethal.

      And descended quickly into an anti-C-section doctors-get-to-their-golf-games screed.

      • Mattie

        Yeh that upset me too 🙁 but their outcomes are better, and their aim is to reduce c-sections to around 20% which doesn’t seem terrible. The article wasn’t very well written

      • Young CC Prof

        Yeah, someone needs to explain to the author that prolonged labor is a major cause of uterine atony and other maternal complications, and that many c-sections are motivated by concern for fetal well-being.

        But I LOVE the fact that someone is doing carts and drills for PPH and other delivery-related emergencies.

        • attitude devant

          We do them. We have ‘Code Ruby’—you call a code Ruby and you immediately have anesthesia, blood bank, lab, and extra nurses with the right drugs at your disposal. But the main thing is prevention: starting pit the moment the baby is out, avoiding protracted non-productive labors, etc.

          • Roadstergal

            Question for you – is the risk of accreta in subsequent pregnancies affected by the surgery itself? That is, is a less emergent/neater C-Section less likely than an emergency yank-it-out to cause complications in later pregnancies, or is it about the same?

          • Young CC Prof

            And prevention can start long before labor, by managing conditions that can increase the risk. I’m getting an iron infusion right now, so I can hopefully have a normal or close to normal level at delivery. Won’t keep me from bleeding, will increase the amount of bleeding my body can endure. At the hospital I’m going to, iron infusions are actually organized by the blood bank.

          • Daleth

            Iron, yes! Glad you’re getting it. They tested me for anemia somewhere around month 3, found I was mildly anemic, and put me on liquid iron with a dose so high it was only available by prescription. Good thing they did, since I lost a quarter of my blood after delivery.

  • Babies don’t naturally overeat, but they can be taught to. The constant slow dribbleof milk that occurs when a mother allows herself to be used as a pacifier has always been suspicious to me as encouraging a baby to get accustomed to literally feeding constantly, and I wonder if that has any effect on infant, and later, child obesity.

    • The Bofa on the Sofa

      Obviously, breastmilk as a baby is not the cause of obesity at age 11. Thererfore, if breastfeeding does cause obesity (as noted, it’s not clearly true), it seems like it is something behavioral that is being learned.

      • The theory is that a baby essentially grows all his fat cells during the first year or so of life, so if he gets fat later, it’s that his already existing cells get bigger, rather than a development of more fat cells. I don’t know how true this is, to be honest. I personally think obesity is multi-factorial, some genetic, some learned eating habits, some lifestyle choices, which is why it seems to be so very hard to lose weight and keep it off.

        • Empress of the Iguana People

          That feels wrong to me. My fat cells ought to be visible without a microscope at this point.

        • Young CC Prof

          Researchers who study obesity tell us that ex-obese people, folks who were obese and have maintained a normal BMI for a substantial period of time, are very rare. They also have one thing in common: All of them continue to actively manage their weight with things like calorie counting, and gain if they stop paying attention. None of them are cured of obesity, they’re just managing it.

          • jumpygiraffe

            Well, I don’t think I am anything particularly special, but I haven’t found that at all. I was overweight and then obese until about age 25 (ish) when I decided I wanted to join the Air Force. I lost 50ish pounds over two years, which is very slow in comparison to the 1 pound a week they recommend. I went from 195 to 145, just within a normal BMI. I am not “thin” by any means, but I haven’t had any real trouble keeping it off the past 15 ish years. I gained a bit when I moved in with my husband and I need to lose about 10 pounds now to get back to a regular BMI, but I’ve been anaemic and really tired. I was worried after pregnancy, but I was back to my pre-pregnancy weight in 2 weeks. I’ve never counted calories, I don’t have an extreme diet. I eat what I want, but not every time I want it, if that makes sense. I did WW got all the stuff, quit the third week and haven’t looked back. But I can’t add my info into any research because I wasn’t followed by a doctor as I lost the weight. I know a few people who have had the same experience. Maybe it was because I lost so slowly, or never yo-yo dieted, or because I was young (ish). But I’m certainly not the only one with this experience. Of course, I’m only 40 now, so we shall see post menopause I guess. Both my parents are seriously obese btw.

          • jumpygiraffe

            But if it was the slow weight loss, I get it. Everyone wants to see results faster than that.

    • Young CC Prof

      My mother breastfed exclusively, but she was having none of this constant feeding business. She firmly believed that feedings should decrease in frequency as baby grew.

      I really do have an issue with the way constant nursing of older babies has been normalized or even held up as an ideal. It isn’t, if there’s adequate milk, your typical healthy 6-month-old should be satisfied with 4-6 nursing sessions per day, plus a little food, all in the daytime.

      The constant nursing interferes with developing proper sleep patterns in the child, makes the mother too tired and overwhelmed to think, and it’s not good for the child’s teeth, either.

    • Well I dribbled breastmilk into the little mouths of all 6 of my children. They are all at normal weights, played sports in high school and one is even an NCAA athlete in college. My 12 year old, whom I breastfed for two solid years, is a very promising long-distance runner. They all outgrew constant nursing just like they outgrew constant diaper wearing – all things happen when babies are ready for them.

    • FormerPhysicist

      I immediately thought the same thing. My children breast-fed and started a whole comfort-feeding habit. Fine as skinny kids, but not so good later.

  • lawyer jane

    Lactivists claim the PROBIT study results are not valid because the babies in the treatment arm were not EBF for 6 months.

    • Roadstergal

      If they had been EBF for 6 months, the goalposts would be moved to ‘EBF for 12 months.’

      The lactivists say ‘every drop counts.’ So more BM should = better everything. But narp…

      • fiftyfifty1

        When lactivists used to say “every drop counts” they meant breastmilk. But they decided that wasn’t enough pressure. Now when they say it they mean formula, as in “every drop counts towards making your baby dumb, fat and unhealthy.”

  • Young CC Prof

    Eh, I read the study, and support for the claim that breastfeeding increases obesity isn’t terribly strong. The confidence interval barely misses zero, and they looked at several metrics, only one of which was positive. The study strongly supports the claim that breastfeeding doesn’t protect against obesity, but actually increasing it? Maybe, maybe not, and not by all that much (odds ratio 1.14).

    • Heidi_storage

      Yes, but imagine if this study had shown a decrease in obesity for breastfed children with exactly the same numbers; the lactivists would be trumpeting it as proof positive that breastfeeding protects against obesity.

      • Young CC Prof

        They’d be trumpeting it with even smaller differences. But I think it’s important to be honest about the strength of evidence even when arguing against people who are not.

        • Sarah

          I think you both make valid points.

        • Sarah

          I think you both make valid points.

  • 3boyz

    Also a friendly reminder that lactivists always tout breastfeeding as aiding mother’s weight loss, and while that’s true for some, they never acknowledge that breastfeeding just as often hinders mother’s weight loss. I’m one of those who just can’t lose weight while breastfeeding. This hasn’t stopped me from breastfeeding my kids for approximately 2 years each, but I do wish someone would have warned me that while it might make weight loss easy, it was just as likely to make it hard. Could have saved me a lot of blood, sweat, and tears.

    • Dr Kitty

      Also the people like me, who lose too much weight when breastfeeding, no matter how much we eat, and who look and feel tired and unwell.
      When my son was 7 months old I ended up losing 2kg over a weekend with Norovirus and my milk supply, which had been plentiful, finally tanked because I was so underweight, so I started combo feeding.
      Not only was he happier, so was I, and I breastfed him for another 8months- but was no longer tired, ravenous and underweight.

      • Sarah

        Yes, but because most women have got the weight to lose, that means it’s never a problem. All of us are the average, remember.

        • Dr Kitty

          Yup.
          I lost 12%of my baseline weight due to vomiting in the first trimester with my daughter and 5% with my son.
          The day after my kids were born I was maybe 6lbs heavier than my baseline.
          Rapid weight loss was *not* what I needed.

          • Kerlyssa

            my mom lost weight- with two 7 pounds twins. she looks like a skeleton smuggling a beach ball in photos.

    • Young CC Prof

      The actual evidence shows that some women lose “baby weight” quickly and easily when breastfeeding, but some can’t seem to lose until they wean, perhaps because for them nursing stimulates appetite too much, and others can’t diet without losing supply. On average, breastfeeding does not appear to increase weight loss.

    • maidmarian555

      That was me too. I stopped breastfeeding just before 6mnths, started losing weight (FINALLY) aaaand then got pregnant again. I’m now 27wks and the size of a house. I do think it’s irresponsible, I’ve a history of disordered eating habits (which wasn’t something that came up in the million questions they asked me at my booking appointment) and I really hung on to the fact that my baby weight would just automatically melt off if I breastfed. I found it very, very hard to accept that it wasn’t going to happen, even after adopting a healthy diet and eating a sensible amount of calories. The frustrating thing is that is was health professionals who kept saying it to me, had it been random people on Facebook that I went to school with I think my expectations would have been better managed.

    • StephanieA

      I lose my baby weight super fast. I also formula fed both my kids. I’ve lost count of how many people ask if I’m nursing because of how quickly I lose the weight- it’s fun to see how surprised they are when I tell them we EFF.

    • Heidi_storage

      I’ve lactated for all 3 kids. First one (a fussy baby who only napped when I was walking her around): Got below my prepregnancy weight 2 months postpartum. Second one (when I exercised less but was making enough for hungry triplets): Lost the pregnancy weight by 5 months postpartum. Third one (the first I’ve been able to feed directly: Am 6.5 months postpartum and 10 pounds above my pregnancy weight; didn’t even start to lost any weight until 2 months ago. Sigh.

    • Gæst

      Yep. I gained weight breastfeeding (first I lost the baby weight, then put 3/4 of it back on). I was just ravenous all the time, but didn’t have time to make healthy snacks, or the fortitude to choose healthy snacks at 3 AM when I just wanted to eat something fast and go back to sleep.

    • jumpygiraffe

      This study in the US found women lost on average 3.2 pounds more at one year if they bf for three months or longer. Which isn’t exactly the hype given. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4312189/

  • Young CC Prof

    The purported dramatic health benefits of breastfeeding suffer from what I call mobius debunking: They keep coming back, and somehow we can never squash more than one at a time. Here’s how it goes:

    Several weak studies are done suggesting a link between breastfeeding and a particular good outcome. These studies suffer from socioeconomic confounding, health status confounding, small sample size, and other issues. Finally, a reasonably large study that controls well for confounders finds no link.

    The conclusion of that reasonably good study is that breastfeeding does not improve X, but because of Y and Z, we should still promote breastfeeding.

    A couple years later, someone does a good study finding no link to Y, but concludes we should still do it because of the effect on X and Z.

    There’s just so much white hat bias, it’s almost impossible to get the myths out of the public consciousness.

    • Kerlyssa

      tarted up gish gallop

  • Emilie Bishop

    I know Milk Meg isn’t representative of breastfeeding mothers by a long shot, but I’ve often wondered if her “mothering through breastfeeding”/”keep on boobin'” philosophies could lead to obesity. If a child is trained to find comfort orally/through food well into their preschool years and that source of comfort isn’t replaced by self-soothing with a favorite toy or something, it isn’t inconceivable to me that those children grow up to become emotional eaters and struggle with their weight. Just a thought that might account for a few cases, or maybe more than a few.

    • Young CC Prof

      This is the Belarus study, from Eastern Europe, which may not apply outside that culture.

      My guess is that, with both obesity and tooth decay, WHAT you feed the baby matters less than HOW. Definitely, a preschooler needs sources of comfort other than food. After the first few months, feedings, whether breast or bottle, should decrease in frequency, that sort of thing.

      • Emilie Bishop

        Right. I agree with cross-cultural observations. Maybe Meg doesn’t have much of a following in Eastern Europe, I don’t know, but alas, thank you internet, she’s not confined to her own corner of Australia, either. Nor is she the only one promoting comfort-nursing well past infancy. The two may not be related, but I just wouldn’t be surprised if they were. Kids’ emotional needs are different from newborns’.

    • J.B.

      There’s also the question of whether it is the milk that is soothing or the sucking. My first child was sucking on something every waking moment. I could not handle that thing being me, eventually she settled on fingers and then thumb. No doubt the lactivists would blame me for her anxiety – but I think the need existed and didn’t require driving mommy insane.

      • Emilie Bishop

        Yes, that would be interesting to know, if possible. My son is 2-1/2 and an avid thumb-sucker. He took a pacifier as an infant but didn’t seem phased when we lost his favorite. He has sucked his thumb since he was in utero (we have an ultrasound pic to prove this). BUT his thumb isn’t a food source. So I don’t know what that will mean later. My husband was also a thumb-sucker and I was devoted to my pacifier, both of us well past toddlerhood, and we’ve both struggled with weight as teens and adults. Neither of us were breastfed, and my son was combo-fed his first two months and then formula after that. Anecdotes, I know, but I do wonder if there’s more connection to all this that will be discovered later. It’ll be interesting to see.

  • Sarah

    Not seen the research, but it’s always surprised me that people are so keen on the idea of breastfeeding being protective against obesity. Seems counterintuitive.

    The ability to become obese more easily, the inclination to eat large amounts of high calorie and high fat foods whenever they were available, these are traits that are advantageous in resource marginal, unpredictable environments. Most humans haven’t lived in societies where they’re a disadvantage. So why would breastfeeding have evolved to protect against it? Logic suggests that if anything, the opposite should be true.