Tomorrow We Diet! is a 1951 Goofy cartoon directed by Jack Kinney.
Goofy (known as "George Geef" in this short) has difficulty trying to lose weight by dieting when his mirror talks back to him.
Home video releases
George gets a "light snack".
"'You are jolly, genial, lovable, and... FAT AS A PIG!?'"
George briefly turns into a rabbit.
George tries boarding up his refrigerator.