Our objective was to clarify how different groups of chronic morbidities are associated with indices of body composition, such as body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), skinfold index (SF), and fat-free mass index (FFMI). Our sample comprised Chuvasha residing in numerous villages in a rural area of the Russian Federation. The investigated cohort included 787 males aged 18-89 years, and 716 females aged 18-90 years. We performed a cross-sectional, community-based study of a large sample of individuals not receiving any medications for treatment or prevention of chronic morbidities. To elucidate the association between morbidity and age-adjusted anthropometrical indices, we used one-way analysis of variance, wherein the above indices were the dependent variables, while individuals affected vs. nonaffected for a specific disease were the grouping variables. Individuals with ischemic heart disease, diabetes mellitus, hypertension, and peptic ulcer showed significant differences in their BMI, WC, WHR, and SF. In the first diseases, mean values of anthropometric indices were higher in affected individuals, whereas in the peptic ulcer group, mean values were higher in the nonaffected. Skin diseases and gynecological diseases showed significant differences in WHR. Mean values in affected individuals were lower than in the nonaffected. The group afflicted with local forms of arthritis showed significant differences in FFMI, suggesting that arthritis is not linked to obesity, but is linked to high lean mass. Rheumatic diseases positively correlated with WC and FFMI.