I am very interested in nutrition and enjoy eating a well-balanced diet because it makes me feel healthier, happier and more energized. I also have a terrible sweet tooth, which I combat by simply not buying junk food when I shop for groceries (although I will indulge on rare occasions). This strategy has worked for me very well — up until now.

I am living with my boyfriend who, despite even his doctor's warnings, has a rather unhealthy diet. In an effort to nudge him in a better direction, I have offered to cook most of our meals at home myself, but with little success. He's a picky eater and often declines the meals I prepare in favor of pizza or Chinese take-out instead. I would just give up and let him clog his arteries, but his unhealthy habits are starting to affect me. When he brings home tacos, or especially bags of candy, I inevitably eat them also. I am a decent cook, but a greasy pizza always tastes better. If I can't change his habits, how do I at least keep him from changing mine?

I am writing in hopes that your answer to this question will help other readers. A few years ago, when I was in college, I discovered that my college roommate was bulimic. My boyfriend and I found evidence in the mornings that she had been vomiting on a daily basis; she also developed weird eating habits (at 6 A.M., she would wake up and buy two pints of ice cream and eat it all, and then not eat for the rest of the day). We didn't know how to address the problem, and were afraid of hurting her. When we called the Health Service, they took the "my best friend is bulimic" line to suggest that I was bulimic instead! I didn't want to become the food "hall monitor" — are you eating? What did you eat today? etc. — but we tried to include her in healthy meals.

Eventually, some other stress factors in her life calmed down and her binge/purge behavior seemed to subside. However, I've always regretted that I couldn't attack this situation head-on. Do you have any advice for people that might be in a similar situation?

Here's a food preparation question: I made a large tomato sauce with meatballs and several pork chops in it. I cooked it for two hours and turned the heat off at 1:00 AM and went to bed without putting it in the refrigerator. I awoke at 8:00 AM and the sauce was a few degrees above room temperature. If I reheat the sauce, will it be all right to eat? Thanks.

1) Which foods, if any, have negative calories?

2) I have recently started a weight loss plan and after doing some research I learned about calorie burning foods. My question is, are there really calorie burning foods or is it just another diet fad?