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I don’t think microwaving in plastic on a regular basis is a good idea, though I admit I do it occasionally. </p>
<p>I gain 20 pounds in college and lost it by biking to a summer job, and did pretty much the same in grad school. It was easy to lose weight at that age by upping exercise and being a little more careful about what I was eating.</p>
<p>I like the idea of broaching whether she wants any advice if you think you can do it. Since she’s mentioned the problem to you I think she would be open to it. You could mention also the possibility that PCOS or thyroid issues sometimes can be the cause of unexplained weight loss if she doesn’t think her diet has changed a lot. I think midnight snacks, drinking soda or fruit juice with every meal, weekend drinking and too little exercise are far more likely causes though.</p>