Fat Cells Slim Up, But Don¿t Ship Out

Fat cells may shrink or grow in size, but not in number, a
new study shows.

The findings, published in the advance online edition of Nature, hint
that it might be possible to create new weight loss drugs that reduce the
number of fat cells.

Fat cells (adipocytes) can get bigger or smaller. But the new study isn't
about how plump fat cells get. Instead, it's about the number of fat cells that
people have.

The researchers -- who included Kirsty Spalding, PhD, of Sweden's Karolinska
Institute -- gauged the number of fat cells in 687 adults, and then compared
that to past research on the number of fat cells in children and teens.

Obese people had more fat cells than lean people. But the number of fat
cells held steady in adulthood, regardless of whether people were lean or
obese. When people lost a lot of weight through bariatric surgery , their fat
cells shrank in volume but held steady in number.

Next, Spalding's team studied fat cells from 35 people. The fat cells came
from fatty tissue collected when the patients had liposuction or abdominal surgery.

The researchers concluded that the fat cells didn't last forever, but died
and were replaced by new fat cells at the same rate, resulting in a stable
number of fat cells.

Tinkering with that balance so that fat cells aren't replaced as quickly
could be a new strategy for weight
loss drugs, note Spalding and colleagues.

It's not that you're born with a certain number of fat cells that you keep
for life. The number of fat cells rose in kids and teens, leveling off by
adulthood, according to the study.

By Miranda Hitti
Reviewed by Louise Chang
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