Diabetes, particularly type 2 diabetes, is epidemic in the United States among adults and children alike, and increasingly prevalent around the world. On its current trajectory, the increasing incidence of diabetes has the potential to ravage both public health and economies. There has, however, been evidence for decades that lifestyle has enormous potential to prevent chronic disease, diabetes included. Studies suggest that the combination of tobacco avoidance, routine physical activity, optimal dietary pattern, and weight control could eliminate as much as 80% of all chronic disease, and 90% of cases of diabetes specifically. None of these factors is necessarily easily achieved, but most are simple. Diet, on the other hand, is complex, and arguments abound for competing diets and related health benefits. From an expansive review of relevant literature, the case emerges that the overall theme of optimal eating for human beings is very well established, whereas the case for any given variation on that theme is substantially less so. Once the theme of healthful eating is acknowledged, the challenge shifts to getting there from here. Although much effort focuses on the wholesale conversion of dietary patterns, the introduction or removal of highly nutritious foods can have direct health effects, and potentially reverberate through the diet as well, shifting the quality of the diet and related health effects. Studies demonstrating favorable effects of daily walnut ingestion in diabetes and insulin resistance are profiled as an illustration, and an ongoing study examining the implications of daily walnut ingestion on diet quality and various biometric variables is described. The line between dietary pattern and the epidemiology of diabetes is indelibly established; we must work to connect the dots between here and there.