Lactation Matters would like to thank all of our readers who left comments about the Implications of Obesity in Breastfeeding Women article. Your comments clearly raised some very important issues about how we, as lactation consultants, should use research articles to guide our practices. Fortuitously one of our guest bloggers, Jennie Bever Babendure, has significant research experience with cellular and animal models of obesity. She has graciously offered her insight into understanding this research article and its relevance to our practice. Again, we thank you for your thoughtful comments about this research study and the conversation it helped to create.
Response by Jennie Bever Babendure, PhD, IBCLC (email: firstname.lastname@example.org)
“In light of the advice given to speak with mothers about the impact of a high fat diet on lactation, it’s important to point out that feeding rats high fat chow (which is also higher calorie) is a way researchers induce obesity in rats. This was done 6 weeks before the rats got pregnant, so they were already obese before pregnancy and lactation.
As a result, this study cannot separate the effects of a high fat diet during pregnancy and lactation from the effects of preexisting maternal obesity. Had the 2 sets of rats consumed the same amount of calories on low or high fat diet, we might be able to draw conclusions about dietary fat’s impact on lactation in rats. However, the rats fed a high fat diet consumed more calories and were obese before they even became pregnant. As such, this study does not provide sufficient evidence to recommend that human mothers consume low fat diets when pregnant or lactating to improve lactation outcomes.
As this study was written for the research community, I don’t think the authors made a point to clarify that they were using high fat feeding primarily to study the impact of obesity, not necessarily dietary fat content, on lactation. In the interest of evidence-based practice, I felt it was important to make this distinction. This study doesn’t demonstrate that consuming a diet with a higher percentage of fat during pregnancy and lactation leads to lactation problems in humans, but rather suggests that preexisting diet-induced obesity leads to delayed onset of full lactation, and changes in the mammary gland in rats.”