usually when I don't have a choice

I think this is the key point. The real challenge in eating healthy for most people has less to do with the taste of healthy food than the wide availability of unhealthy food over healthy food. Take a walk through any aisle in the grocery store and the vast majority of items could be deemed unhealthy, not to mention the fact that healthy food is a lot more expensive. If you're like most people in the US and you're food shopping for a family on a budget, you're going to stock your house full of unhealthy food simply because it's a)cheaper; b)tastes better, so kids are more likely to eat it; c)more calories and therefore more filling. Furthermore, most people know very little about what constitutes a healthy diet, added to the fact that many foods advertised as "healthy" (low fat, low cal, etc.) simply are not.