A toddler doesn’t care if he or she is wearing consignment clothing or sleeping in a used crib. Buy a $30 outfit at a retail store and then another one from a consignment shop at $3 and see if they notice the difference. Save as much money as you can in case something happens and you need the money immediately. Once everyone is healthy and home from the hospital, you can take that saved-up money and put it toward paying off debt if you didn’t need it for the baby. Otherwise if you don't have much debt, most of your money will be going towards the toddlers nutrition. Healthy snacks are not as cheap as you think. In today's society prices of food have gone up. Cereal, yogurts, and chips are pretty expensive when you add everything together. This is when coupons come in handy.
As far as not allowing my child to be fat, cooking healthy meals on a daily basis and incorporating outdoor activities to increase a form of daily exercise.
A challenge with having a baby and keeping them healthy would be eliminating high calories snacks such as potatoes chips, cookies, and candy by substituting with healthy snacks like carrots, celery, and cheese.