Your only job during the Whole30 is to focus on making good food choices. You don’t need to weigh or measure, you don’t need to count calories, you don’t need to purchase everything organic, grass-fed, pastured, or local. Just figure out how to stick to the Whole30 rules in any setting, around every special circumstance, under any amount of stress… for 30 straight days. Your only job? Eat. Good. Food.
The rationale for the Paleolithic diet derives from proponents' claims relating to evolutionary medicine.:594 Advocates of the diet state that humans were genetically adapted to eating specifically those foods that were readily available to them in their local environments. These foods therefore shaped the nutritional needs of Paleolithic humans. They argue that the physiology and metabolism of modern humans have changed little since the Paleolithic era.:594–95 Natural selection is a long process, and the cultural and lifestyle changes introduced by western culture have occurred quickly. The argument is that modern humans have therefore not been able to adapt to the new circumstances. The agricultural revolution brought the addition of grains and dairy to the diet.