Abstract
Numerous studies have shown a positive relationship between intelligence and health, with higher intelligence quotient (IQ) linked to better health outcomes, longer life expectancy, and lower rates of non-communicable diseases. Better health behaviour in the more intelligent (either due to better health knowledge or more advantageous social-financial opportunities) and system integrity theory (overlaps in the background causes of intelligence and health, such as genetic factors) are competing explanations for this link. This study aimed to examine the dietary habits of high-IQ individuals compared to a control group. An online questionnaire was completed by Mensa members (IQ ≥ 130) and control group participants from three countries, assessing various lifestyle factors, especially dietary habits. Key findings include lower smoking rates among Mensa members, special diets primarily for personal rather than medical reasons, and more frequent consumption of some national staples. There was no clear trend for healthier nutritional habits among Mensa members, suggesting that this aspect of health behavior does not account for better health in the more intelligent and supporting system integrity theory instead.