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?

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 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?

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 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?

Do "fat burners" really work? If so, why? If not, why not?

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 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?

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 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.

What is the difference between Ionic and colloidal in vitamins & minerals?

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?

I don't really understand the way daily vitamin supplements work... I take One a Day for Women. My question is, if the vitamins you take are not time released, does your body use them the way intended or are they just a waste of time? Thanks.

Is carbohydrate transformed into fat in the body?

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?