Resisting whining for junk food

Here's an article that touches on how kids often beg more for products if they see a recognizable cartoon character or have been exposed to an item through television commercials. It also briefly describes strategies for dealing with whining and notes that giving in is the worst one. What do you do? What I have found works best with my kids is to talk to them about commercials and how they make unhealthy foods seem like a good thing when they're not. But sometimes that hasn't been enough, either. For quite a while, one of my boys asked for Reese's Puffs cereal because "amazing things happen when you eat Reese's Puffs," as he heard on TV. I talked to him about how it basically is a bowl of sugar that would do nothing to make his body strong, but he was still curious. So one day I bought the darn stuff, poured a small bowl, had him eat it and asked if anything "amazing" was happening. He looked disappointed, and then kinda mad, that he was still sitting in the same old kitchen with nothing new to show for his consumption. He also found he liked the taste of a healthier cereal he's been eating for several years better. I do admit that eventually we finished that box of Reese's Puffs, but he hasn't asked for them again. So maybe if we call commercials' bluffs from time to time, we can help our kids see that what they promise are often not true. Yes, keeping them away from TV and commercials is important, too, but I feel like we need other strategies. What else works?