Fat cell numbers in your teens set you up for life

When it comes to changing your fate as far as fat is concerned the jury is still out on that particular case.

Although research suggests that no amount of dieting will alter the number of fat-hoarding cells in the body, experts remain divided over the issue.

According to scientists in Sweden the number of fat-hoarding cells in the body is set during adolescence and stays the same, regardless of obesity later in life.

Dr. Kirsty Spalding of the Karolinska Institute says when they tested patients who had lost huge amounts of weight they found little change in fat cell numbers which explains why it is so difficult for some people to lose weight and to keep it off.

Dr. Spalding says rising rates of obesity has meant that much of scientific attention has been focused on the "adipocyte", the cell type which makes up the bulk of our bellies and waistlines; when we get fatter, these cells are actually expanding in size.

However it was unclear whether this was the only thing happening, or whether the numbers of adipocytes could go up and down as well.

If they were going down then in theory, losing weight could actually reduce the number of fat cells in the body.

Dr. Spalding's team first tested several hundred children, adolescents and adults of various ages and found that while fat cell numbers increased through childhood, by the time adulthood was reached, the number of cells stayed the same.

Then in order to test the possibility that fat cell numbers could change in extreme circumstances, samples of fat were taken from patients about to undergo radical weight loss such as "gastric banding".

This is considered a last resort, where surgery reduces the size of the stomach and performed to help very obese patients lose weight.

Once the weight loss procedure was complete, another sample of fat was taken to assess if the overall number of fat cells had decreased.

Dr. Spalding says they discovered that the level of fat cells had stayed the same, which is the bad news for dieters even though it explains why it can be so difficult for some to lose weight and to keep it off.

Spalding, a neuroscientist, says losing weight did not make the fat cells go away and they merely shed lipids and shrank in size and the fat cell number seems to be fairly set by adulthood and remarkably stable.

Dr. Spalding says those fat cells are not going anywhere, and are bigger in obese people than in their lean counterparts; she says by the time we are adolescents, the 'game is up' in terms of the number of fat cells we can posses.

While some experts say the research represents a "firm foundation" for further studies into obesity and solid evidence to be used in future research, others are not convinced by the theory that fat cell numbers are set from adolescence.

They say it is known that there are lots of cells in adult fat tissue that do not contain fat, but are capable of doing so if the nutritional conditions are right.

They suggest it is premature to conclude that by adolescence the number of fat cells we can possess is already set.

Dr. Spalding says new therapies that block fat cell renewal might help people maintain weight loss but probably would not be an effective weight-loss remedy unless coupled with restrictions on calorie consumption.

Experts say eating sensibly and exercising regularly remain the key to staying healthy.