If your diet contains insufficient calories or nutrients to fully sustain both you and your nursing child, your mammary glands will have «first shot» at your body's available nutrients to produce highly nutritious breastmilk, leaving you to rely on whatever is left over. (healthychildren.org)
WfPBRunner, Thea, et.al., — Just thought I'd offer up that those of us watching this conversation «get» the points you are trying to make re: insufficient calories overall in the diet (resulting in insufficient protein) is a different issue than an increased requirement of protein in an otherwise calorically sufficient diet in the elderly. (nutritionfacts.org)
Part of this difference could be nutritional as some runners, especially women, experience bone loss due to overtraining and insufficient calorie intake. (cathe.com)