Is leading a life without a diet coke once in a while worth it?

Ken Nelson is blogging about following the recommendations (via Instapundit) in Tim Ferriss's book, The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman. His January 4th entry describes giving up artificial sweeteners:

I’ve been stuck around 190 lbs for a few days. After reviewing the 4 Hour Body “diagnosing problems” chapter, I skipped all artificial sweeteners today. I’d mainly been getting them in caffeine free Diet Coke at lunch, and in Splenda sweetening green tea in the evening.

Well, I had no sweeteners today, and I don’t miss them, and I actually feel pretty good without them.

Tomorrow, I hope to see the weight start to come off again, but even if not, the test confirms that I don’t need the stuff, and I feel better without it.

This dieter is trying to take off weight and feel better. Me, I just want to feel better (if I'm fat, so be it) but I wonder if giving up Splenda is really the answer. I worry that it will just lead to other problems like eating more foods with real sugar. Is leading a life without a diet coke once in a while worth it? I think not...