Partly because I have never and am never going to breastfeed, I am wary about advocating it. I do genuinely believe that women who want to benefit should be given every available support and encouragement. On the other hand, if a woman chooses not to breastfeed or cannot breastfeed for some reason, then as a culture we should be able to allow this situation without judgement or criticism.
While it’s clearly not for everyone, I do believe that, overall, there are compelling reasons to believe that breastfeeding trumps formula feeding. Back in 2006 I reviewed the evidence for the benefits (for both mother and child) here. Near the bottom of this piece I cited some research which links breastfeeding with lower maternal body weight after birth. This provides at least some evidence for the notion that women who breastfeed are more likely to attain their pre-pregnancy weight than women who bottle feed their babies.
However, if a mother is to breastfeed, what would be the best diet for her to eat?
This question was partially answered by a study which is in press at the American Journal of Clinical Nutrition [1]. In this study, two different diets were tested on a group of breastfeeding women at two different times. One diet was relatively high in carbohydrate and low in fat (60 and 25 per cent carb and fat respectively), while the other was relatively low in carb and high in fat (30 and 55 per cent of carb and fat respectively). Each diet was trialled for 8 days. The diets provided very similar levels of calories (about 1800 cals per day).
A number of assessments and measurements were taken during the course of the study. The most notable findings concerning milk production were these:
During the high fat diet, while milk volume was not different to during the high carb diet, the amount of energy supplied by the milk was significantly higher.
This increase in energy was due to a higher concentration of fat in the milk.
This may have particular importance to brain and nervous system development, as certain fats (such as arachidonic acid and docosahexaenoic acid) are thought to play a critical role here.
Turning our attention to the maternal health for a moment, the higher fat diet also led to higher fat metabolism in the mother. Overall, there was a greater ‘energy deficit’ (calories in minus calories out) than when women were eating the higher carb diet too.
Here again, we appear to have evidence that not all calories are created equal when it comes to the impact they have on our metabolism and, potentially, body weight. This study also suggests that a higher fat diet leads to the production of nutritionally superior breast milk. The bottom line is that we have some evidence here that compared to a high-carb diet, a high-fat one may well have benefits for both nursing mother and child.
References:
1. Mohammad MA, et al. Effect of dietary macronutrient composition under moderate hypocaloric intake on maternal adaptation during lactation. Am J Clin Nutr (22 April 2009).