What's the fat story? Why do some gain pounds while others stay thin?

Ok I've been sitting on some info about fat cells, their growth and how it's controlled for many years now. I've also added to it from my own experience in the way my body generally seems to work and how other system in the body also seem to work compared to the fat cells etc.

What am I babbling on about? well read this article http://www.livescience.com/health/080530-fat-cells.html It's naturally presented as new research but I'd heard of this around 10 years agao during my degree. I can remember being in the library looking for some studies re a module I as taking. I noticed in a journal a few studies on leptin and it's relation to fat loss. I know it's sad but this stuff just fascinates me. It's bascially why i did the degree.

Any way the research papers I read, which for the life of me I can't remember what they were etc, explained that at the time Leptin was believed to play a key role in fat maintenance. There were theories that your body tried to keep each fat cell full to a certain degree. Say 50%. there is growing evidence that you can grow new fat cells but very little showing that you can remove them.

The theory went that once you have increased the number of fat cells on your body how does your body know what fat level to maintain. i.e does it care about maintaining the same percentage of fat that it always aimed for. Say 15% or something. A little higher for women. Or does it just care about how full the fat cells are. E.g. when the cells are below a certain percentage say 30% then this triggers something, maybe the brain to raise the levels back up again.

At the time it was a big debate and my guess is that the debate is still raging.

My belief is that it's mch more complex than this because I believe our own habits and behaviours and lifestyles getting in the way. We just seem too good at overriding the natural drivers that we have and this has been shown in animals. many of these aren't so good at overriding their natural instincts compared to us.

Anyway I really liked the explanation I got from these articles because it explained clearly to me why it is that some people can readily put on weight and others can't. Maybe it's not the reason but it works for me. The idea is if you have already put the weight on before and therefore have the extra fat cells required then putting weight on is easy because your body is already able to store a load more fat than it already does. However people who have never been overweight will not have enough fat cells to store the excess fat. They will have to build new cells before the fat can be store.d This is going to take both time and a bunch of energy. So in the short term maybe a motnh or two they won't appear to add on any weight. Then all of a sudden they'll joint the fatter classes of society and become like the rest of us.

I find this idea works in every situation I try to apply it.

• It works perfectly for my own body.
• It works for the idea that young children who are overweight are predisposed to being over weight when they're older
• It works for many people I've met who either find it easy or difficult to add fat weight
• It follows the general principle I have found in the body that once it has found a solution for something it never seems to forget it. In this case it's how to store excess weight

As for whether you can stick at a lower weight or whether your body will always try to maintain an equilibrium at a higher weight than before. I feel that former is possible. I believe firmly the body is more interested in surviving and that it's mechanisms are tuned for that. The levels of fat in our body are crucial for functioning but I expect the storage vesicles are just that. I don't expect the body to take too much interest in a particular cell. I expect it to add up the total amount of fat, make sure it's available where it's reuqired and that there is enough to go round.

That's my opinion anyway.