Sabrina learns how busy teacher Kirk keeps his weight in check. And Ria has a diet that most people would envy.
James struggles to put on weight, in spite of what he eats. Sabrina also meets Margaret and looks for tips on staying slim in her routine.
Karl from Essex is puzzled about why he's never gained weight. Sabrina also meets Gaby from south London. Could her digestive system hold the secret to her keeping trim?