For some reason, I've been gaining weight over the past few weeks. I've just started uni 3 weeks ago and have been quite active - walking a lot, riding my bike to the train station and back (so 20 minutes of riding my bike every day), taking dancing lessons once a week etc. And I've been eating a lot less. Beforehand, I'd been sitting at home all day, eating lots of chocolate and not moving much at all. So now that I actually should lose some weight, I seem to gain weight!? I've gained about 5 pounds (!) over the last 3 weeks, especially around my stomach. What should I do about it?

I'm not sure what would cause that...Try keeping an eating diary for a week or so to keep track of how many calories you're eating and your general eating patterns. I do lose weight when I'm on my ass but it's because I eat a lot less. When you're active you can't run up too much of a calorie deficit because you'll feel weak and hungry and tired. When you're not moving around much it doesn't matter if you feel like that, it's not like there's anything you need energy for. But if you're eating less and moving more I'm not sure what is happening.

I think you've read about my problem with orthorexia, right? Wouldn't be so good for me too keep an eating diary

It sounds stress-related. You're probably retaining a lot of water and not eating makes your stomach semi-dormant. You should always drink tons of water and eat something when you wake up (even an apple) to get your metabolism kicking.

Personally, no matter how much running, biking, skating or whatever I do, nothing fixes my stomach and abs like good old-fashioned crunches and sit-ups.

My whole body would look excellent, but for that little tummy paunch. Sit-ups, crunches, any ab excercises you can pick up. They hurt bad, but look good.

Yeah, that's true.

Maybe your metabolism is just evening out? I don't really know what would be going on unless you're eating more calories. Have you weighed yourself or do you just think you've gained about 5 lbs? Being stressed can make you see yourself as fatter (or it does me, but maybe that's strange). Anyways, give it some time and see if your weight evens out in the near future. Don't obsess too much.