I'm a 22-year-old woman. Many of my friends in their late 20s and early 30s (and older) have been warning me about an inevitable metabolism slow-down and subsequent weight gain around my 30th birthday. They say, "You just wait. When I was your age, I sat around all day eating pizza and I never gained a pound. Now I can't lose weight no matter what I do."

I am sure there's some truth to this, but I DON'T sit around eating pizza all day. I run three to four times a week and eat very healthfully. Will these habits ease the slowing down of my metabolism? Or should I expect some weight gain no matter what I do (as they say will happen)?

I am 18 years old and I am determined to lose a few pounds and tone my body by the end of May. I just began running and I'm starting off by running a mile and hope to work up to a four-mile run four or five days a week. My diet is generally a bowl of cereal in the morning, and a turkey or ham sandwich with some type of fruit and a bottle of water. Dinner is something different every day, but usually healthy. I also have been doing an ab workout for about seven minutes after I run. Is what I'm doing effective? What are your suggestions?

I have a job that is largely sedentary — mostly sitting in an office in front of a computer. My partner's work is very physically active. Since we've been living together, food and nutrition have increasingly become a source of stress and conflict. He needs big meals with lots of protein and calories, and I need better portion control with lots of vegetables. We're having real problems with shopping and menu planning. Since we've been living together, I've been gaining weight and he's been losing! Can you give us any advice or direct us to information on how to live and eat together while addressing both of our nutritional needs?

I am very concerned about my eating and exercise habits. I'm a first-year, and since I got here last fall, I've lost about 35 pounds. I've been exercising almost obsessively and eating a rigid, low-fat diet. I try to eat about 2000 calories a day, but still feel hungry a lot (especially in the morning) and still seem to be losing weight at the rate of about a pound a week. I'm 6'0" tall and weigh 133 lbs. right now; my family and friends are all worried and although I keep telling them I'm not sick, I wonder if I am. I've seen a nutritionist in Health Services; she gave me some advice about good nutrition and what I should be eating, and I've been trying to follow her guidelines, but it's gotten very hard for me to know what is a "normal" diet. Am I anorexic? If I am, what can I do to help myself? I know I could never go to counseling; I'm too independent. Can you give me any advice?

Do you have any suggestions for me on losing weight? I feel so intimidated going to a fitness center because of the looks I get. I really do. It seems like an individual has to be thin to go into fitness centers now-a-days. I should say some of them are that way.

I am currently trying to revise my eating habits to eat less often (I'm a throughout the day snacker, and normally don't eat meals). Is it okay to replace cravings or "boredom eating" with herbal teas? I was told that tea is a no calorie drink, and yet it fills me up when I'm hungry. I have started to replace most of my cravings with tea now, so that I actually eat a lot less than before. Is tea healthy for you if it is no caffeine, herbal, and I use honey to sweeten it? I am not used to drinking much of anything in the day and am fairly slim, so could the extra water intake have any weight gaining effects on me? Could this be a healthy diet?

I have been chewing and spitting large amounts of food (pretty much always sweet stuff — pastries, chocolate, etc.) almost every night for eight or nine months. I am eating a healthy, balanced diet otherwise, maybe a little on the lower caloric side (1300 to 1500 calories per day). My chewing and spitting sessions usually follow a balanced meal. I know this is a type of eating disorder. I have done a lot of research online and I know that there are side effects, although they vary depending on who you ask. Some sites mention that chewing and spitting activates the release of insulin and results in hyperinsulinemia, insulin resistance and weight gain. Is this true? How long would it take to develop these problems? Are these reversible if I were to stop this behavior?