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?

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?

I'm curious to know if going to the gym increases sexual drive? I am a female in my 20s and recently started an exercise routine (running and weights), and I have noticed that my sexual drive has increased significantly. There have been no other major changes in my life, and I have been dating the same man for close to two years now, so I can think of no other real reason why my libido would have increased. Is there any real connection between working out in the gym and beneath the sheets?

I realize dessert products labeled fat free are high in sugar (which can be converted into fat). But which is the lesser of the two evils: high fat or high sugar content?

I know that plants (besides soy) are considered "incomplete" protein sources, because they don't contain all of the essential amino acids. However, why is it that the nutrition facts of many grains and vegetables say they have protein? For example — a serving of pasta has seven grams of protein, corn has twp grams, and chickpeas have six grams. Is this considered "incomplete" or "complete" protein, and how can you know how much complete protein you are eating when you mix, for example, a serving of corn, and beans? I think average people should eat 50 to 60 grams of protein a day, but how can you ever know how much you are really eating if you are mixing incomplete proteins that together contribute to your day's protein requirement?

I frequently hear that beverages with caffeine or alcohol are not good for replenishing fluids and preventing dehydration. But in reality aren't they just a bit less effective at hydrating your body than other beverages? In other words, if you were stuck in the desert with nothing to drink but beer, coffee and cola, would you actually be worse off and die of thirst sooner if you drank these beverages versus not drinking anything at all?

You've been a hero(ine) of mine for quite some time. I hope YOU can answer this question (it seems no one else can).

I've been reaping the benefits of green tea for about a year now, and I feel great! Just recently I began opening the tea bags after brewing, and putting the tea leaves in with the actual brew and drinking the leaves as well. Does this add more health benefits to green tea? I would think so! So far, no one has been able to answer this question directly. Please let me know if you know!

Stay Awesome Alice! May your boards hum forever!

What is the best way to prepare, health wise, before a big test such as the SAT, LSAT, MCAT? What foods do you recommend to keep my "brain moving?"

Does cooking in a cast iron skillet supply any iron to your system? My husband and I have a disagreement.

Does altitude affect calorie-burning? That is, if I do the exact same workout twice — once in New York City and once in Colorado — will I burn more calories at the high altitude? What things DO affect how many calories you burn in a workout?

I have heard that if you exercise/work out in the morning before you eat breakfast that it will cause your metabolism to increase throughout the day, helping you to burn calories. Is this true?

I've read a lot lately about midnight snacking and late night eating and obesity and calorie worries, but my problem lies in the opposite direction — I'm LOSING weight, and insatiably hungry, day and night! The only advice I get is, "Eat healthy," which is preaching to the choir, since I consume more fresh produce, mostly vegetables, and home-cook all my own meals. At a recent nutrition check-up, the nutritionist patted me on the back in congratulations for having one of the healthiest lifestyles he's seen, and shrugged at my inexplicable hunger. The fact is, I'm in the kitchen every other hour, and my body doesn't differentiate between awake and asleep anymore when it comes to hunger. I go to bed on a full stomach, and wake up every three hours to eat again. It's exhausting! I'm falling asleep during the day — but never more than an hour, because hunger strikes. And amid all this, my grocery bill climbs and my weight drops. I don't get it. What am I doing wrong?

I just checked serving sizes for different kinds of nuts, and it turns out that I eat 500 to 1,500 calories worth of nuts every day. I eat a couple of different types (almonds, peanuts, cashews) and nut butters. I've never had a problem with this; I'm on the thinner size of average and feel relatively healthy. I know nuts are healthy for you, but can they be too much of a good thing?

A friend of mine and I were disagreeing about this point and I thought maybe you could help. I have heard that it is not possible to both lose fat and build muscle mass simultaneously: ideally, a person should do cardiovascular exercise with dieting to lose extra body fat, and then start to focus on building up muscle mass. He says it's possible to both burn fat and build up muscle over the same period of time. Which is the case?

I get the apples provided in the dining hall on campus every day and have noticed that they are completely coated with wax (scratching the surface produces white flakes). I was wondering, how harmful is the wax if I eat two or three apples a day?

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?

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?

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?

After practicing yoga in normal temperatures for years, I recently attended a heated yoga class (heated quite hot: 95 to 100 degrees!). The experience left me dizzy, nauseous, and completely enervated. Afterwards, I expressed my concern to the teacher, asking why the studio needed to be so hot. She "explained" that by sweating, supposedly the body releases "toxins" and that my nausea and dizziness must indicate that I need to "detox." Personally, I think I was suffering from heat exhaustion. I've heard this silly explanation more than once, as many people seem to believe toxins are released through sweat. But is that true??? And — next question — doesn't exerting oneself in extremely hot temperatures seem like a recipe for dehydration? Are their any benefits that make it worthwhile, or is all this heated yoga just nonsense?

My friend recently got a blood test back from her doctor and she was told she was deficient in Vitamin B12. She is a vegetarian. What can she do to supplement this vitamin if she does not eat meat?

I know if I cook vegetables too long, they would lose nutrients. How about pasta and beans? Do they lose their carbohydrates and proteins and other nutrients in them if I cook too long? I always cook pasta and beans for over an hour because I like nice and soft and plumed pastas and beans. Am I eating zero nutritious pasta and beans?

I was recently turned away from a blood donation site for slightly low hemoglobin. I'm a menstruating woman and a vegetarian, so it wasn't a big shock. I'm trying to add more iron to my diet in the form of beans and cruciferous veggies and eggs (cooked on cast iron!), but I've run into some confusion. The pamphlet I got from the blood bank suggests raisin bran as a very good source of iron. Several health articles and studies I've found online also point to raisin bran, but others say that wheat bran inhibits iron absorption and should be avoided when trying to raise iron levels. Sometimes the conflicting information comes from the same source! Can you shed any light on this, Alice? Would a bowl of raisin bran a day help or hurt my iron intake?

Is it really true that fasting can help purge the body of toxins? Is fasting safe? I find all kinds of contradictory information about this on the web.

Thanks for your help.

Is it bad for you to drink hard water? Can the calcium in hard water be absorbed by your body and would this be good for you, like the calcium in milk?

I'm a college student and also a bodybuilder. I've become aware of very high protein intake amongst bodybuilders at my gym. I'm skeptical as to consuming as much protein (around 225 grams) a day like the bodybuilders at my gym do. Do bodybuilders need more protein? And if so, how much more?

I was wondering if you could offer any advice as to how to keep from getting that miserable full feeling after eating a big holiday meal. Are there any food combinations it would be best to avoid to keep you from feeling so miserable?

I have recently learned that in order to burn fat as a fuel, your body requires carbohydrate. Up until this point I had been doing cardio training first thing in the morning on an empty stomach, as I had read that this is optimum for fat burning. However, now I have a small carbohydrate snack before I train in order to prevent my body using lean muscle tissue as a fuel. Today I have again read in another book that training on an empty stomach first thing in the morning burns the most fat. I am a little confused over the best thing to do! I train with weights twice a week and do cardio three times per week. I do want to maintain my lean muscle, but am looking to reduce my body fat.

I sometimes can't find the time to cook for weeks at a stretch. During these periods, I live on whole grain bread, cheese, and fruits (usually pears). Oh, and a couple of soft-boiled eggs at breakfast. I feel very healthy, but my friends have told me that this diet is low in minerals. Is this true? If it is, what should I add to it?

Do you have information regarding decaffeinated coffee and its negative health impact? I have heard that the process used to produce decaffeinated coffee, or the ingredients thereof, do more harm than good.

I am a vegetarian and frequently feel like it takes a long time to "wake up" in the morning and some days I feel like I never quite get there. I can't help but think this may be diet related. I went to a doctor for a test for anemia which was negative and I always try to get a good nights' sleep (six to eight hours). In the past I have tried to gain weight and failed miserably. I remain a little underweight but get a good deal of exercise each day. Any ideas?

Is carbohydrate transformed into fat in the body?

Is it bad to exercise while slightly drunk? Some friends like to hike and drink beer. I find that I get flushed easily, and tire more quickly. What's going on?

1) What are your thoughts regarding the use of Splenda as a sugar substitute? I have heard that the body is not able to metabolize this and that it is excreted through the urine. Do you have any current research on Splenda and the side effects? I realize it is a relatively new product. Thank you!

2) I searched the archives and found no information on Splenda or sucralose. Lately, it seems like Splenda is gaining popularity in the crowded sugar-substitute category. It seems too good to be true — measures cup for cup like sugar, you can bake with it and mix it into drinks, and it is made from sugar so it really tastes like sugar. My two questions are... is this a safe product, or are there some disadvantages with the product? And secondly, if it is very safe and versatile, why aren't more companies using it now?

I know it's necessary to have a certain amount of fat in your diet, but occasionally I hear about "good fat" and "bad fat." What is the difference? Is that the same as saturated/unsaturated? What foods have "good fat"? Can I tell by looking at the nutrition label on a food product which kind of fat I'm eating?