No, you're not doing anything wrong. This is a common reaction to improved quality of nutrition. I had the same issue myself! It was SO difficult to reach my minimums. I think it's because our bodies are so starved for good nutrition that it takes less to trigger our appetites. That doesn't mean we don't need to eat; it is important to hit your minimums... remember that because we've been eating badly for so long, we have basically trained ourselves out of understanding our hunger cues.
When you're having trouble meeting your minimums, you DO need to get more intake, but there's some easy ways to boost calorie intake without adding bulk or overstuff yourself. www.sparkpeople.com/resource/nutrition_art