When you are breastfeeding, you need more food and nutrients than normal to provide fuel for milk production. Follow these guidelines. Eat a well-balanced diet that includes about 500 calories a day more than you did before you became pregnant or about 2,500 calories a day for most women. Get 1,000 mg of calcium a day. Check with your physician to see if you should be taking a daily vitamin. Avoid foods that affect the baby. If your baby acts fussy, gets a rash, has diarrhea or congestion after nursing, speak with your doctor. This may be due to a food allergy from your diet. Drink at least eight glasses of liquid a day.