I've posted about that study in the past - see this post of mine from another thread, written in June 2005. Note the comments by the study authors.

My personal opinion (which I've posted before) due to my own experience, is that this might be somewhat Pavlovian - simply, many people are accustomed to eating something with a flavored beverage - think of all the advertising for Coke and Pepsi from the past 50 years (remember "Things go better with Coke"?). Advertising and marketing is highly influential in our decisions in what to eat, what is 'good' and 'bad' or fashionable, etc. (actually, the main reason that Coca-cola's advertisers began to use color advertising featuring food such as burgers and pizza with an icy cold Coke was due to the limitations of color photography at the time in which skin tones would come out really orangey or weird-colored - but there was no problem whatsoever in photographing food. (see the book "Soda Pop: The History, Advertising, Art and Memorabilia of Soft Drinks in America" by Lawrence Dietz).

I always think of the book The Lion, the Witch and the Wardrobe where the White Witch gives Edmund a hot drink and says "It is dull, Son of Adam, to drink without eating". IMO that's pretty much ingrained into many of us - it has nothing to do with the ingredients of diet soda - BTW, there are no 'fillers' in diet Coke; it's mostly carbonated water, with some caramel coloring, flavoring (like regular Coke, made of natural oils and extracts for the most part, I suspect), caffeine and whatever sweetener is used in the verision you happen to be drinking (aspartame, sucralose, or saccharin which is still used in the fountain version in the US).

I think that relationship is more psychological than physiological, people may think "Oh I'm getting this near-zero calorie diet drink, it's perfectly fine for me to splurge by changing to a large fry or getting the deluxe burger."

Aspartame gives me bad headaches, so I don't drink soda sweetened with it or anything. Splenda doesn't effect me in the same way, so I use it. I rarely use real sugar in anything because it does evil things to my blood sugar. And besides, I figure MOST of what I eat is natural/organic.

Sheri:

I stopped using artificial sweeteners about 3 years ago. I wanted to cleanse my body of all impurities before trying to conceive a baby. I ended up getting pregnant on the first try and haven't touched any artificial sweetener ever since. I have read the same things you have about them. I feel I am better off without. I eat fruit or just good old plain sugar when I want something sweet. In moderation of course. I also try to avoid high fructose corn syrup. Not that it's necessarily damaging, but it just has always sounded rather gross to me.

I haven't had a carbonated beverage of any kind in almost 5 months. I feel better off. I drink mostly water, milk and hot tea. I also have the occasional glass of juice and cup of coffee. I have become a bit of a purist during this better eating experience. Not by force, mind you, by choice. I try to stay away from processed and refined foods as much as possible. I like pure, preservative free, real WHOLE foods. My body does too.

Good luck staying off the stuff. I know it can grab a hold of you by the throat some times. Just remember, you're stronger than it!