Helena and Murray have been married for around 22 years, but their weight gain is concerning them. Helena believes that her weight gain is down to the menopause, but Murray is at a loss to explain why he's also gained weight. The surveillance cameras follow their every move to try and discover the truth.

Kelli and Tracey are both due to get married soon but are baffled by how they've managed to put on four stone between them since they met. They agree to allow surveillance cameras being put inside their home to monitor what they eat.

Sharon and Tracy are sisters from Birmingham and are unable to find a reason to explain their expanding midriff. Puzzled at. They agree to allow surveillance cameras being put inside their homes to monitor what they eat.

Lorraine and Cori are dieting mother and daughter from south London, whose massive weight gain is a total mystery to them. They agree to let surveillance cameras being put inside their home to monitor what they eat.

Glyn, Louise and Sue are 3 people whose family fortunes have increased by more than just a few pounds and they’re desperate to understand why they can’t shed their weight.

Lovebirds 22 year old Katie and 24 year old Michael from Kent are a young couple who can’t understand why they’ve piled on the pounds. Not only have they grown up together but they’ve also grown outwards and in the last 4 years they’ve put on a massive 8 stone between them. To find out why their weight is spiraling out of control Katie and Michael agree to surveillance cameras being rigged inside their home to monitor what they eat and in order to get the full picture they are also tracked outside the home by a crack PI team.

Allan and Emma have been together for around four years but their weight gain has made them both determined to solve the mystery of the extra pounds once and for all.