1) What about avocados? I know they don't contain any cholesterol, but they are high in fat so I have avoided them. Now, however, I am reading that the kind of fat they do contain may be useful in lowering cholesterol. Do you have any further information on this?

2) I love avocados and have heard that the different varieties have different health benefits and some are less fattening than others. Please can you tell me about different varieties and which are best.

I recently received an alarming e-mail regarding the dangers of eating Canola oil. Apparently it is made from rapeseed, which is supposedly highly toxic and has been shown to develop cancer in rats. The e-mail also referred me to an article by a Tom Valentine called "The Canola Oil Report." I located the report, read it, and quite frankly, threw out the remaining canola oil I had in the kitchen. Is there any truth to this article? And if there is, surely this is criminal.

I recently had lab work done that identified a vitamin D deficiency. My level was eight and my doctor says that 30 is considered a normal level. I was then prescribed a vitamin D2 pill to help bring my levels up. I just read something that said vitamin D3 is the preferred type to use as a supplement and that 30 isn’t considered the “normal” level anymore, that the number should be closer to 40 or 50.

A few questions: Is it better to use D3 or D2? What level is considered normal? What are the effects of vitamin D deficiency?

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 recently started to stretch to start learning yoga and I have become sore in my muscles, and was wondering if I am sore the next day after stretching, is it okay to stretch the next day when I am still sore?

I've heard a lot of people talking about how coconut oil is supposed to be really good for you, but I also know that it has a lot of saturated fat. Is it actually healthy or not?

My sister has been told by one doctor that eating ice is effective for an iron deficiency. Another doctor says that this is balderdash and not effective.

What is the deal? Which opinion is correct? Why is there no consensus on the feedback physicians give for this subject?

I also would like pointers to more information for this topic.

Thanks.

Why do people find fatty or sugary foods comforting? I mean, what is it in these types of foods that causes the body / mind to see this type of food as comforting or pleasurable? Surely from the point of view of the body, it prefers foods that are high in nutrients — so why do people who turn to food for comfort always turn to fatty or sugary foods that don't offer the body anything? just wondering??? and I hope that made sense because I'm sorry it's quite badly worded!

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.

Why is margarine better than butter when margarine is just oil that is hydrogenated, which means that extra hydrogen atoms are added to oil (liquid) to make it firm? If oil is hydrogenated into butter, there would be no difference between butter and margarine because they would both be saturated fats with single bonds and the same number of hydrogen atoms. Is margarine really better than butter?