What is it that stops people staying thin? Why does skinny success often turn into fat failure as the pounds pile back on? We'll meet people who've lost the weight, but are now overweight again – some even bigger than before.
Celebrity dieter Josie Gibson reveals she's determined not to let the scales go back up, but what will it take to keep the weight off? And how happy is she really?
Meanwhile, Claudia has been dieting for almost half her life, but as soon as she loses the weight, it's a matter of months before it comes back on. Now at 13 stone, can she hold her figure and regain her confidence?
And will Gina and Hayley, two dieters stuck in the same cycle, ever find a way out?
Got Thin, Got Fat Again, C5, 9pm
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