I'm not an expert, but based on my own experience, you sound like a good candidate for blue. Also, if you're getting more than 5 hours of exercise a week, they could even bump you up to red. If you're feeling weak and hungry, I'd definitely recommend talking to your counselor about it at your next WI. When I switched from gold to blue, I figured that it was worth a try for a couple of weeks, and even if it didn't work, at least I wouldn't be burned out and starving during my exams, which were happening at the time. It turned out to be a real lifesaver! Whatever you decide to do, good luck!