The prevalence of obesity and diabetes has been studied in adolescent and adult populations in poor, medically underserved rural Appalachia of West Virginia. A web-based questionnaire about obesity and diabetes was obtained in 989 family members of 210 Community Based Clinical Research (CBPR) trained adolescent members of a network of 18 science clubs, incorporating 142 families. After age-correction in < 20 years old, 50% of both adolescents and adults were obese. The frequency distribution of obesity was trimodal. In the overall population 10.4% had type 2 diabetes, while 24% of adult, obese subjects had type 2 diabetes. A new metric, the family diabetes risk potential, identified a trimodal distribution of risk potential. In the lowest most common distribution 43% of families had a diabetic family member. In the intermediate distribution, 69% had a diabetic family member, and in the distribution with highest scores all the families had a diabetic member. In conclusion, the poorest counties of rural Appalachia are at crisis level with the prevalence of obesity and diabetes. The distribution of age-corrected obesity and family diabetes risk potential are not normally distributed. We suggest that targeting individual family units at greatest risk offers the most efficient strategy for ameliorating this epidemic.