This is an excerpt from Lyle McDonald's new book on training and fat loss for women:  While I said I wouldn’t discuss it much, about the only time that women have an easier time losing fat is when they are pregnant and/or nursing. During that one time period of their lives, every adaptation to storing and/or mobilizing fat actually reverses itself. Lower body fat becomes easier to mobilize and this is clearly to provide energy for breastfeeding. Calories are mobilized from the hips and thighs although, oddly, the triceps often gain fat. Nobody is quite sure why; the best explanation I’ve heard is that it provides cushion for the baby.  Either take advantage of it or stay fat I guess.