Mom Fail: Eating Habits

I did everything right when it came to food and my son was little. Turns out, it didn't really matter. I made him a wide variety of foods, he ate what we ate, including chicken, spinach, fish, all of it. When he was small he ate whatever I cooked, and I was so proud of myself. I used to watch the Pediasure commercials with the picky kids and think to myself in a snarky tone "OR, you could just feed your child a balanced, healthy diet".
Then it happened. Somewhere between the ages of 3 and 4, my son decided that he would prefer to exist on pasta with Parmesan cheese alone. I would have to hide the parm in the back of the fridge or he would take the whole block and eat it. Suddenly, I went from having a child with a sophisticated palate to one who only wanted pasta. I'm not sure how or why it happened, but there was that feeling in my gut that said "FAIL".
When I took him to the doctor for his five year check, he had not gained a single pound in a year. "Pediasure" my doctor said, and the reality that I really had failed kicked in. The worst part about this is that I don't know what to do. The Pediasure is working, he gained 3 pounds in under a month, but that cannot be the long term solution. I try new recipes, but he seems to misunderstand the difference between not liking something and not feeling like it. As soon as I find something he loves, he will eat it for a day, then decide he hates it. I don't believe in the "clean plate club"; however, at some point I think I need to buckle down, cook dinner, and if he doesn't like it too bad. I don't want to starve my child, but I think he needs to learn that he has to eat something other than pasta. He tells me "We always need to try new things, and maybe we will like the way they taste" yet seems to forget that as soon as I set dinner down in front of him. When he starts school next year, heaven only knows what I will put in his lunchbox, a topic I am trying to prepare him for, only to be met with "Plain pasta". I can't help but feel like a failure in one of the most basic areas of parenting, that being feed your child. Any advice?

I did everything right when it came to food and my son was little. Turns out, it didn't really matter. I made him a wide variety of foods, he ate what we ate, including chicken, spinach, fish, all of it. When he was small he ate whatever I cooked, and I was so proud of myself. I used to watch the Pediasure commercials with the picky kids and think to myself in a snarky tone "OR, you could just feed your child a balanced, healthy diet".
Then it happened. Somewhere between the ages of 3 and 4, my son decided that he would prefer to exist on pasta with Parmesan cheese alone. I would have to hide the parm in the back of the fridge or he would take the whole block and eat it. Suddenly, I went from having a child with a sophisticated palate to one who only wanted pasta. I'm not sure how or why it happened, but there was that feeling in my gut that said "FAIL".
When I took him to the doctor for his five year check, he had not gained a single pound in a year. "Pediasure" my doctor said, and the reality that I really had failed kicked in. The worst part about this is that I don't know what to do. The Pediasure is working, he gained 3 pounds in under a month, but that cannot be the long term solution. I try new recipes, but he seems to misunderstand the difference between not liking something and not feeling like it. As soon as I find something he loves, he will eat it for a day, then decide he hates it. I don't believe in the "clean plate club"; however, at some point I think I need to buckle down, cook dinner, and if he doesn't like it too bad. I don't want to starve my child, but I think he needs to learn that he has to eat something other than pasta. He tells me "We always need to try new things, and maybe we will like the way they taste" yet seems to forget that as soon as I set dinner down in front of him. When he starts school next year, heaven only knows what I will put in his lunchbox, a topic I am trying to prepare him for, only to be met with "Plain pasta". I can't help but feel like a failure in one of the most basic areas of parenting, that being feed your child. Any advice?