This diet involves humans consuming what is assumed was eaten by people in the Paleolithic period, which spanned between 2.5 million years ago until 10,000 years ago. The foods under this diet include consuming grass-fed raised meats, fish, eggs, fruits and veggies, nuts and roots. The Warrior Diet was a concept originally created by Ori Hofmekler, who sought to develop a diet which would replicate the athletic bodies which were present in the times of the Romans and Greeks. Ronda Rousey's diet is handled by a gentleman named Chad Waterbury, who is a believer in the principles that were laid out by Ori Hofmekler's Warrior Diet.
One of the tenets of Hofmekler that Waterbury incorporated into Rousey's dietary regimen was eliminated carbs during and immediately after training. This allowed Rousey burn fat and shift from fighting at 145 and get herself down to 135, where she now competes. Some may be curious about training on an empty stomach, but part of the diet's philosophy is geared to the hunter-gatherer days of humanity, where we would be most prone to activity, which consisted of hunting and gathering, on an empty stomach.