You can take certain parameters like bleeding time ,clotting time , PT, APTT, Platelet aggregation, Lipid profile, CRP and subdivide the population into 1. Obese 2. over weight 3. Normal weight and compare them with each others
or You can divide them as 1.Smokers 2. Non smokers
or You can can divide them as 1. Exercising life style 2. Sedentary life style
Comparison of these parameters will provide the effects of life style on them