Presented by Dr Dawn Harper, Fat Family Tree uses cutting-edge genetics to decode the genes of an overweight family for whom all other attempts to shed the pounds have failed.
Discovering how the family's genes have put them at risk of excessive weight gain is the first step to devising a diet to help them beat their genes.
Based on the latest science, the programme's 'gene-busting' diet also promises failsafe diet tips that could help all of us lose weight.
The McConnon family from Stevenage have all spent their lives battling with their weight and failed time and time again to shed the pounds.
Like lots of people they believe their family history of obesity could be down to their genes. Mum Tina and her daughters Lisa and Karen are all desperate to lose weight.
All three take a unique DNA test to find out if the genes they have inherited could help explain their weight problems.
Can they change their weight and their future by identifying exactly how their diet and lifestyle clash with their genetic burden, and making the changes to lose weight successfully for the first time?