Hmm. We hadn't heard of the diet to which you're referring, although if such a thing exists, we figure it's probably pretty heavy on the complex carbs. For a game like poker, which can involve marathon tests of endurance at the table, you need that same slow-release energy source that also forms the staple part of the diet of long-distance Kenyan runners, who have dominated their sport for years. However, regardless of whether you agree that poker's a sport or not, no one can argue convincingly that it's at all physically strenuous, so the sugar that also forms a significant portion of those marathon-runners' daily caloric intake, with its ability to quickly re-stock muscle-glycogen stores, would not be advisable for those who spend most of their time sitting down and doing nothing more active than pushing bits of plastic around or clicking a mouse.
Although we can't help you with the diet, we did come across something relevant while researching this answer: a new energy drink especially formulated with poker players in mind and endorsed by none other than Phil Hellmuth. The first press release we came across was dated March 31 and we did wonder if the whole thing was an April Fool's hoax, but we contacted the manufacturer and it all seems to be legit.
Pro Player, we understand, is a citrus-flavored, "crisp and refreshing" energy drink with more caffeine than Mountain Dew, but less than Red Bull, which has been specially formulated to provide focused endurance and energy. It contains added ginkgo biloba (to oxygenate the brain and increase memory and alertness, allegedly), green-tea extract (same deal, plus antioxidant properties for general good health), and acetyl L–carnatine (for mental clarity). Other ingredients include other favorites of the energy drink brigade, including Taurine, caffeine, and B-vitamins.
"I'm excited about this refreshing product because it can truly change the way you feel during a long poker session," noted 10-time WSOP bracelet winner Hellmuth in a very unscripted-sounding press release. "Pro Player pumps me up for several hours without the crash and burn, allowing me to stay focused on taking out players. It also tastes great. With Pro Player, I can almost taste my 11th bracelet."
If you'd like to taste the drink yourself, it's due to be released across the U.S. (and Europe and Africa -- interesting to see how it fares with those Kenyan runners) next month. Or you can order some online now at www.shop.drinkproplayer.com -- it's $48 for a case of 24 cans.