Here in Ohio, we have had the good fortune of picking the brains of some Ohio State University Dairy Science professors and graduate students on milk synthesis at the cellular level. (Fascinating stuff!) One of the comments made at a presentation by a graduate student was that for humans, milk making is not very calorically expensive. Cattle will actually waste their bodies away making milk (since they are bred to resist the autocrine control of milk). Dairy scientists can hardly figure out how to get enough calories into the cattle to prevent them from wasting. Another tidbit I picked up back in '85 from a presentation by Richard Naeye, MD. He worked on the Collaborative Perinatal Project (I have the article, but the source is not on it.....). They found that when pregnancy weight gains were low in the project, fetal and neonatal mortality rates were much lower when hands and facial edema was present than when it was absent. The lowest perinatal mortality rates in the collaborative project were in low weight gain gestations in which women were thin and developed edema. Fetal and newborn survival were also greater when women's third trimester hemoglobin values were below 12 mg/dl, the lower values reflecting hemodilution. Higher hemoglobin values may have reflected less blood volume expansion and resulting low uteroplacental blood flow (impairing nutrient delivery to the fetus). If the human is as efficient at making milk as the dairy people believe, perhaps a mother is at less nutritional risk because of breastfeeding than we would think! The age of the BF baby also is important since the older baby probably needs less milk (if over 12 months). I also think that the risk to the mother and fetus of continued breastfeeding needs to be weighed with the risk to the breastfeeding baby (the original case was an 8 month old, I believe) of sudden weaning, ABM, decreased immunity, etc. etc. I agree with Arly that the mother needs to eat a nutritious diet and take supplements when warranted. ( I see very few women whose diet is terrific enough that they are meeting all their needs.) I usually counsel mothers with short interconceptional intervals that they need to pay especially good attention to their diets since with the first baby, if they did not eat a particular nutrient that there might have been some storage supplies in the "pantry". Frequent conceptions do not give enough time to "restock the pantry." They seem to understand. I also use Linda Smith's "Rule Number One is Always Feed the Baby". The only way pregnant women can do this is to eat often. I also caution against fasting longer than 8 hours because ketones that are released may adversely affect fetal brain development. Whew--sorry for the verbiage leak!!! Martha Grodrian Brower RD LD IBCLC Dayton, Ohio