Actress Natalie Cassidy, best-known for portraying podgy teenager Sonia in Eastenders, lifts the lid on her secret past of fad dieting and investigates where these so-called 'celebrity diets' come from, who's doing them, and whether any of them actually work. She meets 20-year-old Vikki, who's been trying these fad diets since the age of 12, and together they try the extreme maple syrup diet, which reduces calorie intake to just over 300 per day.