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?

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?

I have been a lacto-ovo vegetarian for three years now. I want to stop and get back to eating meat. I do not know the proper way of doing this, so I would love feedback on how to plan my meals.

I eat lots of different kinds of lentils but don't know much about their individual nutritional properties. Are certain kinds of lentils healthier than others? What are the different calorie and protein figures for different kinds of lentils?

I read on someone's blog about drinking seltzer water if you're trying to quit drinking soft drinks but still need that fizz. Are there any good/bad side effects to drinking seltzer water?

I have a question about dehydration. I am an eighteen-year-old female and play on a varsity basketball team. We usually have two-hour practices in which we work very hard. Our coach does not give us water breaks, and usually by the end of practice, we have cottonmouth and are "dying" for water. It is horrible. Is there any way that not having water during that time can be dangerous? Sometimes the team can feel sick or weak by the end of a practice.