Don't kill yourself. 450 calories for a bagel and cream cheese, which (for me, at least) is a full breakfast, doesn't seem too bad. Assuming you're an active guy, I'd imagine your caloric needs are probably around 2500/day, so your bagel represents only 20% of that. There are also plenty of options out there for low fat cream cheese, low carb or whole wheat bagels, and just about everything has a low-sodium version.