My soccer coach is suggesting we eat bananas at half-time of our soccer game to rebuild our energy for the second half. I understand that bananas are a very good source of energy, among other things. I don't see any detriment to this idea, but my question is this: Does the consumption of bananas result in an immediate energy boost? I have always been led to believe that food must be digested through the system before the body realizes the benefits, and that usually takes several hours. Can you enlighten me?

Why is it I can always run a greater distance on a track than I can on a treadmill? On a track, I can run five or six miles, but on a treadmill, I can only go a maximum of three or four, then I tucker out. Is it because I get more bored on a treadmill, or is there a more physical explanation?

Is egg powder an effective egg substitute for protein?

How can you tell when you're full? I am not over-weight, but I tend to over-eat. How can I know when to stop?

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?

Are there other types of eating disorders other than anorexia and bulimia? For example, I have this fear of unnecessary fat in food and eat everything "plain," that is, without butter, oil, dressing, or sauce, etc. I thought that it's good that I'm this health conscious, but my friends say that it's a little obsessive. Is this an eating disorder?