What are the best foods to eat and to avoid while breastfeeding?

Good balance. Eating healthy, well balanced meals is the best diet for breastfeeding (and for everyone for that matter!) be sure to eat a wide variety of foods; your baby is exposed to the different flavors thru the breastmilk so make sure you eat lots of veggies. Stay hydrated by drinking at least 64oz a day. Avoid highly refined and processed foods.
Eat a balanced diet. All over the world, women breastfeed their babies just fine. These women have very different diets from one another, yet as long as they eat balanced diets with a good variety of foods, they should do well with their breastfeeding. A breastfeeding mom may choose to avoid a food that she suspects is causing a change in a baby's behavior, and should discuss this with the doctor.
Well balanced. While breastfeeding it is important to eat a well balanced diet and to stay well hydrated. This allows the maximum benefit for the production of the breast milk while providing the baby with the best nutrition. Avoid overuse of caffeine and artificial sweeteners as these can affect breast milk production and your baby's belly.
Eat a balanced diet. There are no better foods for the breast feeding mom than a "well balanced diet." mothers should also drink sufficient quantities of fluid to prevent thirst. Include deep sea fish twice a week in your diet plan to ensure getting enough dha (omega-3 fatty acid ) which enhances neuronal development in infants' brain.
Generally No Worries. Eating a balanced diet is important. Some foods may affect the digestive system with gas or fussiness. This is determined by trial and error.Also avoid caffeine and other drugs which can pass thru the breast milk to the baby.
Avoid Dairy. Breast milk is best because it is human/mother's milk. Some babys are sensitive to small amounts of foreign protein that can be absorbed by a mother and transferred to her milk. If a baby has gassy /colicky symtoms, a trial of no milk or dairy in mom's diet sometimes makes a huge difference. Spicey or greasy foods can sometimes have a similar affect and may need to be avoided.