Love on a Diet (Chinese: 瘦身男女 - literally "Slimming Men and Women") is a 2001 Hong Kong romantic comedy film produced and directed by Johnnie To and Wai Ka-fai, starring Andy Lau and Sammi Cheng.

The film reunites Lau and Cheng, who last paired up in 2000's Needing You.... For their roles, both actors play obese characters and had to wear fatsuits with prosthetic makeup.

A suicide attempt causes her to meet Fatso (Andy Lau), a Hong Kong salesman working in Japan who is also obese.

To earn enough to finance Mini's weight-loss programs, he opens a boxing gig on the streets allowing on-lookers to punch him to vent their pent-up frustrations.

On the night of her reunion with Kurokawa, Fatso drops Mini off at Tokyo Tower and she meets up with former beau under the gazing eyes of the local media.