Married... with Children (1987)

S1E2 Thinnergy

Marcy presents Peggy with the health book "Thinnergy," which sparks a newfound motivation in her. Excited about the possibilities, Peggy starts a diet and urges her family to join her, but they all decline. As Peggy becomes increasingly bothersome due to her diet obsession, Steve steps in and persuades Al to participate in the diet as well. Eventually, Steve manages to convince Peggy to abandon her dieting efforts.