Q: I gained about 20 pounds having my son and lost it all in about 4 months from breastfeeding alone (I was not eating the best or exercising). I know that the body burns major calories to produce the milk but do you think some of the calories burned might have come from muscle?

A: Chances are, yes, some of those calories came at the cost of muscle since you didn't exercise at the time which would've 'encouraged' your body to hang on to muscle a little more. However I wouldn't be too concerned with it because you did gain 20 pounds of fat in preparation for this period, so the majority of the lost weight should've been that fat. Whatever muscle was lost and whatever fat was gained you can certainly rectify the situation now with an exercise routine and a good diet.