Diet while breastfeeding?

Betty
I am 5 weeks post partum and I really want to start trying to get my old shape back. I have 30lbs to lose! I have started working out but I was wondering what I should eat and not eat while breast feeding. For example I read that lettuce & tomatoes give baby gas, so are salads out of the question??! What are some meal ideas that worked for you that are both nutritious & healthy while not too fattening?