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Friday, 30 May 2008

Research on Breastfeeding

Thanks to everyone for the great discussion about breastfeeding issues in exercising, dieting women. Let me try to clear a few things up based on what I've read in the current medical literaure. And no one on runango can accuse me of citing "obscure research" this time.
Lacation, diet & exercise

1. Lactating women need 330-500 calories/day more than non-lactating.

This is to address Carrie's comment (I really enjoyed your math, but it looks like you may have overestimated the amount of milk produced per day). I really, really take issue with the BFing taking 500-700 cals/day. The Bois is probably eating 35 - 40oz a day. There are 20 cal in each ounce of milk. So he is ingesting ~700-800 cals, but for sure it must take more cals for your body to manufacture it, KWIM?

The energy cost of exclusive breastfeeding from birth through six months postpartum is 500 kcal/day. This estimate is based upon the average volume of milk produced (780 mL per day), the average energy content of milk (67 kcal/100 mL). In well-nourished women, the energy cost of lactation is subsidized by mobilization of tissue stores (approximately 170 kcal per day) I assume these are tissue stores you have built up during pregnancy... if anyone can explain this better, I'd love to hear it. Therefore, the recommended dietary allowance (RDA) for energy is 330 kcal per day more than nonpregnant, nonlactating women.

DRI, Dietary Reference Intakes: For Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients). Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food, and Nutrition Board, Institute of Medicine. National Academy Press, Washington, DC 2005.

2. Most studies indicate that lactation has little effect on post-partum weight loss (didn't come up, but just an fyi). The biggest factor affecting your post-partum weight is how much you gain in pregnancy (see previous posts from when I was pregnant).

1. Brewer, MM, Bates, MR, Vannoy, LP. Postpartum changes in maternal weight and body fat depots in lactating vs nonlactating women. Am J Clin Nutr 1989; 49:259.
Dugdale, AE, Eaton-Evans, J. The effect of lactation and other factors on post-partum changes in body-weight and triceps skinfold thickness. Br J Nutr 1989; 61:149.
Öhlin, A, Rössner, S. Maternal body weight development after pregnancy. Int J Obes 1990; 14:159.
Schauberger, CW, Rooney, BL, Brimer, LM. Factors that influence weight loss in the puerperium. Obstet Gynecol 1992; 79:424.
Parker, JD, Abrams, B. Differences in postpartum weight retention between black and white mothers. Obstet Gynecol 1993; 81:768.
Greene, GW, Smiciklas-Wright, H, Scholl, TO, Karp, RJ. Postpartum weight change: how much of the weight gained in pregnancy will be lost after delivery?. Obstet Gynecol 1988; 71:701.

3. You need at least 1500 calories/day to maintain your milk supply.

Reduced maternal energy intake has a limited effect on milk volume, unless dieting is extreme. In one study, dietary restriction to 1500 cal per day for one week did not reduce milk production. However, daily milk volume decreased 15 percent when less than 1500 cal per day were consumed.

1.Butte, NF, Garza, C, Stuff, JE, et al. Effect of maternal diet and body composition on lactational performance. Am J Clin Nutr 1984; 39:296.
Michaelsen, KF. Nutrition and growth during infancy. The Copenhagen Cohort Study. Acta Paediatr Suppl 1997; 420:1.
3. Hennart, P, Vis, HL. Breast-feeding and post partum amenorrhoea in Central Africa. 1. Milk production in rural areas. J Trop Pediatr 1980; 26:177.
van Steenbergen, WM, Kusin, JA, Kardjati, S, de With, C. Energy supplementation in the last trimester of pregnancy in East Java, Indonesia: Effect on breast-milk output. Am J Clin Nutr 1989; 50:274.
Brown, KH, Akhtar, NA, Robertson, AD, Ahmed, MG. Lactational capacity of marginally nourished mothers: relationships between maternal nutritional status and quantity and proximate composition of milk. Pediatrics 1986; 78:909.
Imong, SM, Jackson, DA, Wongsawasdii, L, et al. Predictors of breast milk intake in rural Northern Thailand. J Pediatr Gastroenterol Nutr 1989; 8:359.
de Kanashiro, HC, Brown, KH, Lopez de, Romana G, et al. Consumption of food and nutrients by infants in Huascar (Lima), Peru. Am J Clin Nutr 1990; 52:995.
Orr-Ewing, AK, Heywood, PF, Coward, WA. Longitudinal measurements of breast milk output by a 2H2O tracer technique in rural Papua New Guinean women. Hum Nutr Clin Nutr 1986; 40:451.
9. Prentice, A, Paul, A, Prentice, A, et al. Cross-cultural differences in lactational performance. In: Human Lactation 2:Maternal and Environmental Factors, Hamosh M, Goldman AS (Eds), Plenum Press, New York 1986. p.13.
Strode, MA, Dewey, KG, Lonnerdal, B. Effects of short-term caloric restriction on lactational performance of well-nourished women. Acta Paediatr Scand 1986; 75:222.

3. Weight loss does not affect milk production.

Moderate weight loss with or without exercise does not adversely affect lactation (in women with a normal or above normal BMI). In one study, breastfeeding women were randomly assigned to an 11-day program of diet, diet plus exercise, or control at 12 weeks postpartum. Weight loss averaged 1.9, 1.6, and 0.2 kg in the three groups, respectively, while milk volume and composition and infant weight gain were similar during the short study period.
Longer periods of dieting are also had no adverse effect. In one report, 22 of 33 women who completed a 10-week weight reduction program lost an average of 5 kg. Daily milk production was similar at the beginning of the study and 10 weeks (759 versus 802 mL).

5. Your current BMI won't affect milk production.

1. Dewey, KG, Heinig, MJ, Nommsen, LA, Lonnerdal, B. Maternal versus infant factors related to breast milk intake and residual milk volume: The DARLING Study. Pediatrics 1991; 87:829.

2. Butte, NF, Garza, C, Stuff, JE, et al. Effect of maternal diet and body composition on lactational performance. Am J Clin Nutr 1984; 39:296.

3. Michaelsen, KF. Nutrition and growth during infancy. The Copenhagen Cohort Study. Acta Paediatr Suppl 1997; 420:1.

6. You won't lose bone mineral density for good.

Bone mineral content declines during lactation, and compensatory remineralization occurs after you stop breastfeeding and normal cyclical menses start again.

1. Kent, GN, Price, RI, Gutteridge, DH, et al. Human lactation: Forearm trabecular bone loss, increased bone turnover, and renal conservation of calcium and inorganic phosphate with recovery of bone mass following weaning. J Bone Miner Res 1990; 5:361.
Lamke, B, Brundin, J, Moberg, P. Changes of bone mineral content during pregnancy and lactation. Acta Obstet Gynecol Scand 1977; 56:217.
Specker, BL, Tsang, RC, Ho, ML. Changes in calcium homeostasis over the first year postpartum: Effect of lactation and weaning. Obstet Gynecol 1991; 78:56.
Sowers, M, Corton, G, Shapiro, B, et al. Changes in bone density with lactation. JAMA 1993; 269:3130.

7. Exercise doesn't affect milk production

Specifically, aerobic exercise does not affect milk volume. In a randomized trial, volume and composition of breast milk and infant weight gain were comparable for exercising lactating women and controls.

Dewey, KG, Lovelady, CA, Nommsen-Rivers, LA, et al. A randomized study of the effects of aerobic exercise by lactating women on breast-milk volume and composition. N Engl J Med 1994; 330:449.

8. Protein and mineral content of milk do not change with the mother's diet. Fat and vitamin content DO change with a mother's diet.

I regreted my oatmeal diet when I read this.

See Uptodate Article Maternal nutrition during lactation by Nancy F. Butte, PhD for #8 and more on this subject.

Switching to Solid Foods

1. The optimal time to start adding solid foods is 4-6 monts of age. There is no nutritional advantage before this and the baby needs the tongue and neck motor skills that allow safe eating.

s.a and mommy dearest had some concerns about introducing solid foods too early. Here is what I learned.

Interestingly, one study notes that by 4 months of age, most infants usually have doubled their birth weight. When infants have doubled their birth weight, and weigh at least 13 pounds (5.9 kg), they may need to begin supplementing their liquid diet with additional foods to support growth and satisfy hunger [10] . The Bois actually doubled his birth weight (to 12 lbs) a long time ago and he now weighs 14.8 lbs... I no longer blame my diet or exercise for his hunger!!!!!

Committee on Nutrition American Academy of Pediatrics. Supplemental foods for infants. In: Pediatric Nutrition Handbook, 4th ed, Kleinman, RE (Ed), American Academy of Pediatrics, Elk Grove Village, IL 1998. p.43.

Holding off on the introduction of solid foods until after the infant is 6 months of age may cause decreased growth because of inadequate caloric intake, iron deficiency, delayed oral motor function and/or dislike of solid foods.

1. Committee on Nutrition American Academy of Pediatrics. Supplemental foods for infants. In: Pediatric Nutrition Handbook, 4th ed, 2.Kleinman, RE (Ed), American Academy of Pediatrics, Elk Grove Village, IL 1998. p.43.
3.Guthie, HA. Introduction of solid foods – Part 2. Consequences of early and late timing. In-Touch 1998; 15:1.
4.Underwood, BA, Hofvander, Y. Appropriate timing for complementary feeding of the breast-fed infant. A review. Acta Paediatr Scand Suppl 1982; 294:1.
5.Illingworth, RS, Lister, J. The critical or sensitive period, with special reference to certain feeding problems in infants and children. J Pediatr 1964; 65:839.

The Benefits of Breastfeeding

This is just a reminder of the many, MANY benefits of breastfeeding. Popular media can sometimes make it seem like there is controversy over whether or not breastfeeding has advantages for the infant... but read below and hopefully you will agree with me that it should be a CRIME to not breastfeed an infant if you are able to do so...

1. Increases IQ (measured at 27 years of age)

Breastfed ≤1 month: 99.4
Breastfed ≥1 to 3 months: 101.7
Breastfed 4 to 6 months: 102.3
Breastfed 7 to 9 months: 106.0
Breastfed >9 months: 104


1. gastroenteritis
2. respiratory disease
3. otitis media
4. urinary tract infections
5. sepsis

Provides long term benefits against

6. obesity
7. cancer
8. coronary artery disease
9. allergic conditions
10. diabetes mellitus type 1


11. neurodevelopmental outcome
12. cognitive development
13. visual function
14. hearing function
15. stress reduction

See Uptodate article Infant Benefits of Breastfeeding by Richard J Schanler, MD

Of course, I'm not even getting into the maternal and economic benefits.

So what am I going to do with this information? Eat a more varied diet, supplement The Bois with formula until he's four months (that's is a little over a week) and then start rice cereal fortified with iron (assuming he has good enough neck and tongue control). And again, I don't blame my diet or exercise for the inadequate milk supply considering how much he has grown since his birth and what a little artist he is.


Carrie said...

Hey there! Wow, you have done a lot of research.

I bet some of the discrepancy between my estimates and yours for baby's milk consumption is due to the size difference of our babes! My DS was 18 lb 10 oz at 4 months old (I didn't realize the Bois was so much smaller). I am quite sure that my DS was eating 35-40 oz a day based on what I was able to pump just during the work day (28 oz or so), and he still was taking 4-5 other feedings a day.

I found this formula on infant nutrition needs: 120 kcal a day per kg. So my DS would have needed about 1000 kcal a day, or 50 oz, at 4 months old. I don't dispute that he was a large baby though! (He was 8lb 3oz at birth). He was over 20lb before I introduced solids. I don't doubt that (as your research mentioned) some babies do need solids sooner. Babies are different of course.

Also, re: the studies that cited that weight loss does not impact lactation, I'm guessing all or nearly all these moms had much more fat reserve to lose than you did (or I did for that matter). So research on "normal" PP moms might not totally apply. I'm just throwing that out there. I truly felt like my lactation WAS impacted by losing too much weight. But then again, I had a big baby and was quite thin to start with. I wonder if that has been studied.

Sounds like you have a reasonable feeding plan! Good luck. It is enjoyable reading about others' experiences.

Danni said...

The only thing I would point out is that the 1500 calorie minimum likely assumes that you're not burning 1000 calories a day with exericise, which leaves you with a net of 500 calories. If that makes sense. It would seem to me that if you need 1500 calories and you burned 1000 calories/day you would want to eat at least 2500 calories.

One thing too, only because it seems like you don't distinguish, is that a person may have a BMR of say 1200, which means they need 1200 calories/day to keep everything functioning properly, but unless that person is on bed rest she will usually burn an additional 500 or so calories by being awake and doing basic activities like sedentary work. This doesn't relate to today's post it is just something about nutrition that seems to get ignored.

As you might be able to tell, I like to talk about calories. Sad I know! Due to my endless struggle with weight I've learned a lot and while I'm no expert I know probably more than I need to know, so I'm not just talking out of my ass. My problem at this point is execution not information ;)

Anyhow, good job with all this research. "Knowing is half the battle." G.I. Joe.

Phatgirlslim said...

I just wanted to clarify that I wasn't so much concerned with you introducing other foods to the Bois at this point but more with substituting solid foods for the amount of breastmilk that you thought he wasn't getting. Plus i wasn't referring to how many calories he was getting per day but his nutrition as a whole. It isn't possible for them, at this age, to eat enough of a varied diet, to get all of the nutrients he needs to keep developing properly. Not harping on you here, just defining my point. I'm glad that he's gaining weight, it shows that he's been getting enough so far! One extra thing with the breastfeeding. If you're looking to stimulate milk supply, try hand expressing after he's finished nursing to completely empty your breast. I always found that doing it by hand did a better job of emptying than a pump. It did the trick (except for the last one) for me to get milk supply established.

Allison Chapple said...

To Danni's points, I totally agree. Most womens' BMRs are between 1300-1600 (meaning, energy needed just to lie in bed all day, to keep organs working, etc.). Add to that activities of daily living (walking around, driving, showering, sitting...) and you are up to near 1700-2000. Add to THAT energy expended exercising (using 1000 for you), you're up to 2700-3000. Add to THAT breastfeeding...

You get the picture. I am not trying to be a pest, but 1800 cals cannot be enough for a breastfeeding woman who is running as much as you are. I would eat that on a rest day (at least!).

I see all of your research, but just try to think it over a little bit. Research also shows that there is a point where your metabolism slows because it is not getting enough fuel. Your body will go into "save" mode to store the calories that you are giving it. I see this phenomenon all of the time with my patients. They restrict enough and the weight loss stops, or plateaus, because their bodies are saying, "No! No more weight loss! I am going to hold on to every little calorie you're giving me!!"

Lecture're a smart cookie. Just take care of yourself!

sea legs girl said...

Good points about me probably needing more than 1500 a day to maintain a good milk supply being so active. It's a hard experiment to do to figure out exactly how many when The Bois is most likely needing more milk, too. I just wanted to put together a good reference on lactation for active mothers with the research I could find.
I would love to get clarification on one of the points made by the chapples (if you happen to read this). SR and I have been discussing how it does not seem physiologically possible to lower one's bmr with dieting. If you lose muscle mass or become less active because of the dieting, needing less calories makes sense, otherwise your bmr should stay the same. Do you have any references you could point us to about metabolism slowing as a result of dieting?


H said...

"In well-nourished women, the energy cost of lactation is subsidized by mobilization of tissue stores (approximately 170 kcal per day) I assume these are tissue stores you have built up during pregnancy... if anyone can explain this better, I'd love to hear it. Therefore, the recommended dietary allowance (RDA) for energy is 330 kcal per day more than nonpregnant, nonlactating women."

Remember that it might mean more for you, too, as you did not build up quite the amount of tissue stores as other pregnant woman (less weight gain), and you weigh less now than you did prior to pregnancy-- correct? So you won't have the subsidy.

Danni said...

I'm not one of the chapples but there are some links in the footnotes here that relate to the topic:

I've not read the links and only skimmed the little blub so I don't know what the say. I'm just flexing my Google prowess muscle :-)

sea legs girl said...

Thanks so much for the links, Danni! It is interesting how the actual results of research can be twisted on the internet. Here is the conclusion of one of the studies cited on the page at the link you gave:

"Energy restriction produces a transient hypothyroid-hypometabolic state that normalizes on return to energy-balanced conditions. Failure to establish energy balance after weight loss gives the misleading impression that weight-reduced persons are energy conservative and predisposed to weight regain. Our findings do not provide evidence in support of adaptive metabolic changes as an explanation for the tendency of weight-reduced persons to regain weight."
Weinsier RL, et al. Am J of Clin Nutrition 2000.

Allison Chapple said...

I guess I am just an idiot then. I might as well hang up my hat and find another career.

sea legs girl said...

Dear chapples,
I'm sure you're kidding, but I wouldn't give up your career based on one study! I'm sure you'd have many disappointed patients!
There may be more controversy surrounding this issue than this one study shows. We wouldn't be scientists if we didn't constantly adjust what we believed and practiced based on research, right? And you may end up changing my mind on this in the long run... I've only got one reference here.

H said...


I have no studies to back it up-- but I do have the personal experience of stopping weight loss at dramatic levels of Caloric restriction and exercise, and being able to lose weight at greater food consumption levels-- which made me a believer in the possibility of slowed metabolism (at least temporarily, I don't believe it gets stuck that way) with severe diet---- my body actually started showing up positive for hypothyroidism--- though it may be jumped to too quickly in a lot of situations--
That, and it makes sense that the body has adaptations to survive even in periods of food shortage.

It was taught as fact in school for me (majoring in Exercise Science, minor in nutrition) -- but I don't have the studies referenced off the top of my head.

Fast Bastard - World's Fastest Hematologist said...

I've been wanting to write something on here for a while. Hopefully, Sealegs won't mind. This calorie debate has spurred my interest, I guess.

First off, my lady should eat a few more calories for herself and the Bois. What she is doing, though, is not dangerous or unsafe to either of them.

The notion that the body can somehow slow down its metabolism is hard to defend scientifically.

I thought about this sentence ("The Chapples" talking about the bodies response to calorie restriction):

"No! No more weight loss! I am going to hold on to every little calorie you're giving me!!"

I believe this makes sense when talking to patients, because calorie restriction rarely works anyway. Most patients need to get off the couch and start working out.

However, the commonsensical belief that the body can "hold on to calories tighter" after starving is not scientific (as Sealegs showed). There are many ways, calorie restrictors lower their metabolism, such as muscle loss, less activity etc. But. But. But. A cell is a cell and energy is energy. There are only so many pathways to transfer energy and these pathways do not change. A myocute expends the same amount of calories to produce one energy unit, regardless of what the mothership is eating.

If a way existed for animals to, say, run a 5K with less energy expenditure, every animal would use these energy pathways.

So there you have it. There is no way the body "holds on to every calorie", at least in a scientific sense. I would not have a problem telling this to patients, however, but that's another issue.

I hope this post won't get erased...

Allison Chapple said...

But I don't work with regular patients who "need to get off the couch." I work with women with eating disorders. Women who restrict their calories to extremes. I also work with a lot of athletes who restrict and I see this phenomenon again and again and again. So, I am not published on the subject, but I see it with my own eyes day after day. I work directly with a nutritionist - we share our patients. We were talking about this very topic yesterday: when our patients start eating MORE calories, they often LOSE weight! Again, we're talking about people who are already underweight or at least on the low end of "normal." I stand by my opinion. I can't argue with what I witness.

sarah said...

Hmm. I am no nutritionist, but isn't it possible that our bodies perform optimally at a certain caloric level (say 2000 calories a day for an average, active woman). At this level, our reflexes are quicker, our bodies are more awake, our brains our more active. Possibly we fidget more because we have more energy. This might be the optimal survival level (for a cave person, at least), because if you are surprised by a lion, you are most alert and ready to flee, and your brain is fueled so you are more able to think of other ways to survive. But cut calories down below 1000 calories/day, and the metabolic rate slows. The body worries more about immediate survival (not starving) rather than long-term survival (brain fueling) and readiness for lion attacks. So the heartbeat slows, or we sleep more, or fidget less, or are generally less alert and using fewer calories. Running a 5k takes the same number of calories, but the body in "starvation mode" is less likely to want to (or be able to) run a 5k.

I think I've seen studies that people who fidget are skinnier than people who don't. Doesn't this result fit in with my theory as well? I think this is what people mean when they say metabolism is much more complicated than those BMR calculators would have you believe, and why you can't do exact math with calories in vs. calories out.

Fast Bastard - World's Fastest Hematologist said...

Sarah C, I think that's the perfect explanation for how "real life meets science". Very good post.

The Chapples, what do you do if you're not a dietician?

Allison Chapple said...

Are you asking me what my career is? I am a LPC (Licensed Professional Counselor) and CEDS (Certified Eating Disorder Specialist). And recovered anorexic.

I do agree that we can't use an equation to come up with the perfect caloric intake to use globally for every 25-year-old woman, for example. Our individual bodies are a lot more specific than that, and our caloric needs are based on a lot more than just how much we exercise. BUT, I would be hard-pressed to find a professional who would agree that 1800 cals is enough for an breast-feeding athlete.

Again, I am only going on circumstantial evidence here - not a formal academic study - but to me, I put a lot more credence into something I witness numerous times than ONE study that argues it.

Fast Bastard - World's Fastest Hematologist said...

Not to beat a dead horse but I did start out by saying that my lady could eat a little more. 1800 is definitely not enough. And she is eating more, actually.

I just want to make her run faster. I think she is on the light side now, in that respect, and probably needs to gain a pound or two.

I would be interested to see a study proving long-term slowing of metabolism from dieting.

I agree that starving people move around less, fidget less etc, but I would argue that their basic metabolism for the amount of work they are doing stays the same.