I work with a few diet-obsessed women. They drive me mad with their thirty-minute conversations about the calorie/fat content of things like coffee creamer. I'd had enough one day, so this conversation ensued:
"You should try the Sex Diet."
Ears perk up. Eyebrows raise. "What's that?"
"It's the diet where you have so much sex you don't give a fuck how fat your ass is."
[cue crickets chirping]
The diet chatter dramatically subsided, at least when I'm around. I highly recommend this tactic.