robomatic, I think - but don't know the full evidence - that crash dieting e.g. The Biggest Loser TV show type of dieting, losing weight, then going back to bad eating habits and gaining weight can lead to yo-yo dieting and this can affect the metabolism. This is just a quick reflection on some of the things I have read or seen on reputable, scientific documentaries.

One thing I remember hearing about was that after the fat cells in a person's body are reduced in size they still have the capacity to get larger again - or maybe they multiply - but the problem lies in having a large fat storage capacity and then reducing that capacity and then increasing it again, especially time and again.

I'm just about to go out so I can't research it and give you more specific information but it might be worthwhile looking into that.

Ultimately, in my opinion, it comes back to changing eating habits *for life* to a healthy, balanced diet with lots of good nutritious food and a healthy lifestyle and not falling into the trap of losing weight and then *rewarding* myself with junk food and then spiralling back into old bad habits.