It's another of those Eat Well for Less and Secrets of the... (takeaways, supermarkets) type programmes.
A family or friends are interviewed to tell us how virtuous they are with their food. They are very often well overweight but they! They then go off to do a shop "unknowing" that they are secretly being watched, except that the aisles are full of cameras and microphones and so is their specially selected trolley.
It always turns out that they were telling a pack of lies.
"The shop" is never anything like what they said they usually bought so it is either a fix or their initial lies were for effect so that the programmes can make a (healthy eating / savings) point.
I used to like EWFL but these spin-offs are a con.