http://www.ncbi.nlm.nih.gov/entrez/...st_uids=9392477

OKAY! here's some actual evidence that I believe, I think. the link is above, but here's the gist of it for those of you who want it short and simple:

John Prins and colleagues get pre-fat cells (not actually fat cells, but can become them under the right conditions and are the source of making more of them) and fat cells from OBESE liposuction patients for all their experiments. In this study in 1997, they found that these fat tissues contained high amounts of a protein called Tumor Necrosis Factor alpha (TNFa) in the fat of these OBESE patients. This protein does a lot of stuff with the general idea of preventing the accumulation of even more fat, so picture that by the time you get to OBESE, your body is actually trying to help keep you from getting more fat, sort of. Anyway, they wondered if this TNFa protein could also lead to fat cells getting killed off as a way of preventing increases in fat storage, and found that it does (tested in the cultured cells only, not in actual people).

So the conclusion is that there is a protein that is present at higher levels in OBESE people, which is capable of causing fat cell death, and therefore killing fat cells MIGHT be one of the jobs of this protein, TNFa.

One caveat is that the protein TNFa is present at high levels in OBESE people's fat, not necesssarily in the fat of people who have lost weight. One other thing that TNFa does is to signal production of high levels of leptin, which reduces growth of fat cells. One thing we do know (I can provide the links for these articles too, but I'll have to look for them so ask if you want them) is that LEPTIN levels DECREASE DRASTICALLY as we LOSE WEIGHT (which is thought to be why continued weight loss after the first few weeks is harder, and how people think refeeds might work). This would indicate that the levels of TNFa probably (assumption, not fact here) decrease as well as we lose weight, making it LESS LIKELY that fat cell death occurs after weight loss, at least in the shorter term. Maybe after years of maintenance TNFa and leptin levels are able to re-increase (that's a BIG STRETCH by me, though).

the good news is that fat cells are probably dying inside your stomach if you're obese. :P Cheers!