I've been reading some of the background material from one of the articles that appeared in The Wall Street Journal 4-27-2010, in the "Personal Journal" section which today featured Health and Wellness. There were several controversies in other articles: I scanned two: chocolate as a potential antidepressant vs. chocolate being consumed more by those who are depressed; sun-lovers and benefits from sun exposure vs. shade-seekers and harmful effects from excess sun exposure.
The one I was most interested in was titled "A Case for Those Extra 10 Pounds." This one seemed aimed at those who are carrying a little extra in the hips and thighs, rather than the belly. It quoted lots of medical data suggesting there might even be some benefit to a "few extra pounds," an increase in estrogen production and an accompanying decrease in osteoporosis risk; a Dermatology article was quoted as saying that women who are overweight appear younger than those who are of normal weight or underweight.
So let's go back to basics. One third of all adult Americans are frankly obese, not just a few pounds overweight. They clearly have a higher risk of a number of serious diseases. Many of those in the middle ground between normal weight and obesity, i.e., those who are termed "overweight," carry excess belly fat as well as extra poundage in the thighs and buttocks. I see this all the time in the men's locker room at our gym; my wife says she also notes the same in women. Those folk are also at risk of cardiovascular disease, high blood pressure and, according to some sources, even some types of cancer.
On the other hand, in general, it's not healthy to be underweight People who are underweight may be so because of underlying diseases such as cancer. I should, of course, note that some people who are very slender may be perfectly healthy and are thin because of lifelong exercise (long distance runners come to mind).
We all tend to look for excuses and to rationalize our issues away. So if you're lean around the midsection and carry a little extra elsewhere, perhaps you are okay. But I'd suggest you should take a good hard look at your waistline before concluding that you're one of the folk who can safely carry some excess pounds or not.