Cold water swimmer Mary has no problem stripping down to her costume to brave the icy waters of Lough Neagh every Sunday. How she looks doesn't bother her in the slightest, but what her extra weight is doing to her health very much does. Having piled on the pounds year on year for over two decades she is suffering more and more from increasing aches and pains. In the water she is weightless but out of it, she struggles to go about her day to day activities. Mary is the heaviest she has ever been, eating packets of biscuits at a time and family bags of crisps in one sitting. She knows it's not good for her but can't stop. She thinks learning to make healthier options alongside Stephen in the kitchen might give her the impetus she needs to change.One of the most well-known and respected chefs in Northern Ireland, Michael Deane enters the kitchen with the most unusual ingredients, all local and readily available but unknown tastes for Stephen and Mary. Will Michael be able to convince them to buy into his healthy food or will they prefer to stick with the sweet fatty foods they are familiar with. Mary is determined her cookery experience will kick start her weight loss, and the actual outcome leaves everyone stunned.