The study shows that eating habits are less healthy among men, young adults, the less educated, and among the lower class.
Meanwhile, a similar share of the adult population is living an active lifestyle, but the share dropped somewhat over the four years since the previous such study.
Smoking is also rather widespread in Slovenian society, with almost 20% of adults smoking, and a considerable number of children and youth are exposed to smoke.
One in two adults drinks heavily at least once a year, whereas one in ten drinks more than is recommended.
An average Slovenian worker sits an average five hours on an ordinary work day, according to the survey, termed Behavioural Habits Related to Health.
Around a quarter are under stress very often or on a daily bases, and have problems managing it.
In the four years since the previous such study, the number of those exposed to stress at work increased.
Two thirds of Slovenians brush their teeth at least twice a day, and slightly over 61% trust vaccination.
The use of seat belts in vehicles has significantly improved since 2001, but 20% of those surveyed still not fasten the seat belt if they sit on the back seat.
Judging by the results of the survey, the institute has assessed that Slovenians do not take care of their health well enough.
The group at the biggest risk is young adults, where unhealthy habits such as drinking, unhealthy eating, smoking and not enough physical exercise, accumulate.
More than 12% of people aged 25 to 34 have three of the four unhealthy habits, whereas the share among those aged 65 to 74 is slightly over 5%.
Nevertheless, the institute said that those taking part in the survey rated their health better than they did in the previous four surveys.