I played for a long time before upgrading to .05 and felt the same way as you do after I did. After reading that post from Arthur, I began to view the fed bar in a different way and it has really helped me a lot. Rather than seeing a full fed bar as meaning "well fed" you have to learn to see it as "overly stuffed." Eventually, you'll get used to the idea of a half full stomach being normal and not having to buy as many groceries is nice for the bank account as well.

Illnesses that hit just after you have closed the game for the night or for a day at work or terrible. They eat away at our little people's health and eventually their happiness levels drop as well. If that wasn't bad enough, most are contagious and quickly spread to other family members. Treat them as quickly as you can when you return. Check family members' status and see who has the lowest health. Check the store for fruits and vitamins.
If someone immediately displays another illness upon being treated, they need vanco. If they display another illness within a short period of time, they need penicillin. Teenagers will be leaving home soon and if they are not near dangerously low health, should be left alone to recover health on their own. Children are also resilient and have a long time to recover health. (In the meantime you won't be missing out on them working toward pay raises or promotions.) If the antibiotics are needed, keep in mind that they will decrease health further a small amount and will completely zap energy levels. Fruits will help to replace lost health, but are sometimes hard to get in the store. They also act as rewards, so make sure your little person is doing something you want to praise when you give it to them.
Hope that helps!