MISUNDERSTANDING OBESITY: What cats can - and can't - tell you. I have three, and they exactly verify Martin's observation. Two, Shadow and Daisy, are normal; the third, Diamond is, well, fat. Yet all eat exactly the same meals.

Read the comments for a plethora of studies, opinions, and discussion, but the gist, to me, is this. One, the laws of thermodynamics hold: if you ingest fewer calories than you expend, you'll lose weight. The trick, of course, is in the expenditure side, which is complex and highly individualized. And two, for most people to lose weight, just eat a bit less and/or exercise a bit more.

I never had a weight problem until I started commuting 30 miles to work every day. I ate a bit more (breakfast in the car) and exercised a bit less (2-3 hours sitting in the car every day) and wound up gaining ... about 5 pounds a year. Now that I've quit commuting, I'm losing weight (albeit much more slowly than I put it on).