The story was about winners of slimmer of the year, or similar. People who lost lots of stones of weight. They almost all put it all back on.
What I took from the programme was that the science says that it is so difficult to continue to stay slim because your body goes into survival mode and tells you that you need food.
It explains all the yo-yo dieting that women, in particular do.
The moral to me is not to allow yourself to get fat in the first place. The reality is that most people think they can always slim down, but they can't.
If they knew that once fat, you will be like that for the rest of your life, they may not let themselves get into that state.