I think you're right to a degree. Completely depriving kids of treats and sweets may ultimately backfire. OTOH, my kids didn't know when to stop with candy and cookies even when I wasn't limiting what I brought into the house. As I mentioned before, one of my daughters actually ate so much candy at school on Valentine's day a couple of years ago she spent the whole night throwing up. Did she learn from the experience? Nope. She did the same thing on Easter at her Grandparent's house. This was at a time when we had a cupboard full of things like Oreos and snack size Milky Ways which they were allowed to have a couple of every day (and would sneak more when I wasn't looking).
It's interesting that this discussion is taking place now. I just heard a report on NPR this afternoon as I was waiting in line at school for the kids to get out about childhood obesity and eating behaviors. One of the experts that they interviewed point blank stated that most children, especially young children, will not moderate their eating behaviors on their own. Their parents need to set boundaries and guidelines and then stick to them along with educating their kids on healthier choices. He also stated that in order to get kids to change their eating behaviors, everyone in the household needs to participate in changing their eating behaviors or the kids will wind up feeling resentful and develop sneak-eating behaviors when they are being restricted and nobody else is. In other words; everyone needs to follow the desired eating habit or it won't work.
If anyone is interested, the audio of the program is available at WWW.NPR.ORG and the show was Talk of the Nation (Tuesday's show).