As far as we know, there are no studies performed in
which subgroups with elevated clustering were defined. Although we can only speculate, a possible underlying factor in the strong relationship between
smoking and alcohol consumption in the youngest age
group may be the degree of self-consciousness, which is
generally higher in younger adults. It is, however, difficult to explain the higher tendency of clustering between two risk habits in subjects who perceive their
health as very good or excellent (with the exception of
alcohol and fruit/vegetable consumption). Maybe subjects who believe their health is excellent do not directly experience the risks associated with an unhealthy lifestyle.