The energy cost of producing milk is about 500 cal/day. The nursing mother should drink about 13 cups of liquids each day to prevent dehydration. A gradual weight loss of 1 lb/week is safe and does not reduce milk supply. What is the recommended daily energy intake for a nursing mother?
1) 1500 cal/day
2) 2000 cal/day
3) 2500 cal/day
4) 3000 cal/day