Training & Nutrition - Weight loss issues?

Hi, I am planning on losing about 30lbs of excess weight in the next 1-2 months to get back into shape to start winter training for next year's tri season. I've managed this kind of weight loss before by excercise (125-150 miles on bike and 20-30miles a week running all at various HRs and distances), and diet (no alchohol, no artificial sugars, lots of fruits, pasta, water, and fiber). I am curious though because alot of people mention the negative effects of rapid weight loss. I know the risks of rapid weight gain, but dont really know any of the risks of rapid loss except the problem of sustainability.

I think the problems usually associated with rapid weight loss are "usually" because of the "way" people do it (weird diets, medicines, herbs, etc...). If you are doing it just by heavy training (which I assume you are used to) and well planned food intake, then I don't think it would really be a big deal.

one of the biggest risks with rapid los comes from a protein-deficient diet (some liquid diets, not eating) in that teh body breaks down any available muscle for the proteins it needs, which included the heart and can lead to heart attacks in a short period of time. that being said, my understanding is that 2-3 lbs a week is no prob (30 lbs in 2.5 months) and slightly higher shouldn't be too bad. my question would be why not just work a little harder during the rest of the year and keep it off? going up and down rapidly in weight is rough on the systems and can lead to bigger problems than being heavy or too rapid loss.