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?

1) I've started counting calories in order to lose weight, and I've lost ten pounds in six months, so I'm positive that counting calories works. Recently I've started to eat one big meal (about 1400 calories) a day. Is this healthy? Will I continue to lose weight?

2) During the day, I keep a strict paleo diet and end eating at 10PM and Begin eating at 12 PM the next day. Around 10:30 AM the next day, I do full a body weight training session and begin eating at 12 PM. Basically, I only drink water during my fast or keep calories to a five calorie maximum. After the fast, I eat whatever I want (paleo that is). I'm trying to get my body to use excess fat as energy, therefore causing me to lose body fat and gain muscle faster. I feel great and I have witnessed fast results, (increased strength and leanness) within a month and half of intermittent fasting. My question is do you think intermittent fasting is unsafe? Or just a new an effective way to see increased health?

I was bulimic for about four or five months and went from 5'6.5" at 115 pounds to 95 pounds. I have not told anyone, and will not, so please don't ask me to, but I am back up to 110 to 112 pounds and pretty much graze throughout the day so I don't throw up. I mostly snack on white bread, fruit, potatoes, and cereal in large portions, but want to stop and eat a healthy, more balanced diet. The problem is, I am not sure what a healthy weight should be. Charts say I am too skinny, but I don't believe it because I know girls in the media are thinner than me and they seem fine. I want to be as small a weight as possible without being unhealthy. I skipped my period for three months but did get it in January. I have not lost any weight since then though, and I should have gotten my period about a week ago but didn't. I don't understand, it is so confusing, can you help me?

1) A friend and I were discussing this. We both try to stay healthy by eating well (high fiber, low fat, lots of veggies, fruit, etc.) and living an active enough lifestyle (hiking, rock climbing, biking, etc.) that we stay in shape. The question we have, then, is what the current "rules" are for appropriate weight/height ratios? Or are such measurements now thrown out in favor of body fat percentage measurements? She's 5'1" and I'm 6'1" and we're curious what the medical rule of thumb would be for how much each of us "should" weigh...mostly because we're wondering if it takes into account things like muscle mass. What would the current medical/health industry recommend each of us weigh? Are these numbers accepted or are they seen as not as important as they might have been 20 years ago. If you have actual numbers, we'd be curious to see that too. Thanks! I have a dinner riding on this!

2) Could you clarify the Body Mass Index deal? According to one BMI chart, I am "slightly overweight" because I am 5' 5-1/2" tall and weigh 160 lb. I am also very muscular and have a large frame. The lower BMI readings are labeled "ideal," but I've heard muscle weighs more than fat, so if the chart does not include the muscle factor, is it basically saying that it's "ideal" NOT to have extra muscle? I look slender and have never been told by a doctor to lose weight. I'm a twenty-four-year-old female, lacto-ovo-vegetarian, and get lots of exercise, including walking and frequent "sweaty" workouts.

My husband and I are having a debate over the value of liposuction as a means to permanent fat removal. He has read that we are born with specific number of fat cells and therefore believes liposuction has the ability to reduce the number, resulting in permanent fat loss in the areas that are surgically treated. I differ in the belief that fat loss and its permanency depends on maintaining and correcting diet that is related to metabolism. I also maintain that there is no such thing as permanent fat loss from liposuction. Have you an answer to our debate?

I've been trying to diet for over two years. My goal is to lose about 25 pounds, but the most I've been able to get is 15, and I can hardly keep it off. I concentrate on eating very little and since exercise is so hard to keep up, I pretty much starve myself to death. I manage to maintain the weight for a month, and then I lose control again. I've been thinking about the various diet products in the market, such as diet teas, herbs, meal- substitution shakes, and other medical products. I'd like to know what kind of side-effects they have, and how effective they are. (Some boast a seven-day plan, but that seems hardly believable.) Also, I'd like to know how well-researched the information is on these products (i.e., are they long-term enough to cover all the side-effects?) As for aspartame, is it really harmless, or is it just not researched yet?

I am a female, five feet tall and about 127 lbs. I am not satisfied with my size. I am not obsessed with weight but with the way I look. I am very strong and have plenty of muscle. It just happens to be covered by a thick layer of fat. Yes, it runs in my family. On my father's side everyone has trouble with their weight.

I am writing to you because I don't understand why I am not losing weight. I am a vegan. I have no dairy products and no fat content in my diet. Except for the occasional pat of margarine and fried falafel, I don't see why I haven't lost weight because I just cut the dairy products out about two months ago. I have been a vegetarian for 9 years. I ride a stationary bike twice a week in my target heart rate zone. I work out with weights and do calisthenics in my room every night. What is wrong? Is there another factor I am not considering? Glands? Do I just need to be patient? I like being big, I just don't want it all to be fat.

Thank You.

Is there any danger to taking ephedra (ma huang) for weight loss?

In attempting to preserve lean body mass, what is the relationship of body composition to caloric need: Is it true that no matter how lean a person is, the same amount of calories is needed to preserve lean body mass or the leaner a person is, the more calories are needed to preserve lean body mass? Which one is true? And thank you.

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 a 22-year-old male. I would like your advice as to how to increase my weight. I am extremely thin, and would like to put on weight for both appearance and strength purposes.

I believe that thin people have a very fast metabolic rate. Is there any way of slowing this rate down? Does it fall naturally with age? I have often been told that I should lift weights, but cannot find time on a regular basis to do so. I do, however, have time to do push-ups at home.

Anyway, I'd much appreciate it if you could give me guidelines as to how to increase weight, especially through diet. What kinds of food should I be eating? How many times a day should I eat? How big should the meals be? I hear the soybean is very nutritious — is this true; if so, what could I eat or drink that contains soy?

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?

What are the advantages of eating five or six smaller meals per day, as opposed to three meals per day? I've heard it helps to lose body fat. Also, are there advantages to eating more of your calories early in the day?

When working out in the gym, machines, such as treadmills and stationary bikes, show how many calories you are burning. Are these calculations correct, or is it just something to keep the participants happy?

My friends and I disagree — can you settle the dispute? I feel a calorie is a calorie no matter what time of day that you eat it. They say that if you eat all of your calories early in the day, that it is less fattening, because you will be moving around burning off those calories. I say that if you eat 1800 calories a day, it doesn't matter if you eat them in five meals or ten meals, it is still 1800 calories. I believe that the idea of not eating anything after 7 p.m. helps you to lose weight because you cut out the high calorie, high fat foods that are often eaten late in the evening. They say that by not eating after 7 p.m., you lose weight because you're not moving to burn off those calories. Please settle the dispute. Thanks.

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 have a question about walking for weight loss. My walking buddy believes the theory of walking distance is what helps you lose weight best versus my theory that it is the speed at which you walk that matters. So, could you help me figure this one out? Which matters most in ultimate weight loss: speed or distance?

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?