First, you get a couple guinea pigs and put them within earshot of your kitchen.
If you feel like snacking and get up to rummage around in the kitchen, they go absolutely insane. It starts with subtle little squeaky noises, then amplifies slowly up to an ear-piercing WHEEK WHEEK WHEEK WHEEK and if you don't stop what you're doing immediately and redirect your efforts to finding lettuce, carrots, spinach etc. it's not going to stop. If you try to avoid the kitchen by, say, just keeping a bag of chips by the couch, they'll hear the bag and that'll trigger the alarms too. All of these sounds lead them to believe that they are entitled to a fresh vegetable treat, it doesn't matter how much you give them or how much fresh hay is in their cage, they will always demand more.
Eventually you'll realize that you can't just go get yourself a snack. You'll avoid eating altogether and just like that, watch the pounds melt away.
Don't you loooooove meeeee?! Then I WANT FOOD!