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.