In the first episode, Tom calls the group to a sports faculty at a local university to reveal what they have signed up to for the next two months.

It's the first full week of the challenge and Tom is back in Gloucester, the city where he grew up, to exercise and cook alongside his diet and fitness gang. As team chef, he wants to get them off to a good start on calorie counting - and familiar, comforting dishes is the way to go. Window cleaning brothers-in-law Dan and Alex volunteered for the challenge because of health concerns and a normal day sees them tucking into a big, calorific breakfast and grabbing fast food between jobs, but Tom joins the boys on a bike ride in the local countryside before giving them a tasty breakfast muffin to try.

The volunteers are short on time for cooking and exercise, so Tom offers solutions to keep them on track, including quick and delicious recipes, and tips for planning ahead. For the first recipe, Tom makes a pot of beef mince - the starting point for some of the nation's favourite dishes. He uses the batch to make a cottage pie, while the rest is frozen to be used later, perhaps for chilli con carne, spaghetti bolognese or lasagne.

After a positive first couple of weeks, the temptation of unhealthy treats and alcohol is threatening to undo the group's progress, so Tom shares a series of recipes to help the volunteers with their temptations for unhealthy treats. He starts with his own take on Asian crispy duck pancakes, before demonstrating how to make fudge chocolate brownies which are lower in calories. Later, Tom visits Lauren in her home, where he gives her a lesson in making prawn and avocado rice paper rolls which contain lots of fresh, healthy ingredients.

The chef demonstrates how to make healthy dishes full of exciting flavours and textures, including Spanish-style squid and a chickpea and chorizo stew. Meanwhile, the group are invited to take part in a martial arts session, before Bev persuades the gang to try out her favourite workout, a vigourous dance class called Clubbercise. Later, Tom invites the whole gang over for lunch, where he prepares an easy chicken tray-bake, full of aromatic Moroccan flavours.

In the final episode, the chef and the group of volunteers discover how much weight they have lost over the past two months, and how much fitter they are as a result of all their hard work. To celebrate their achievements, Tom decides to throw a special picnic by the river, and whips up a series of exciting, healthy recipes they can all enjoy.