Intake of nutritional supplements among people exercising in gyms and influencing factors

Objective: To assess supplement intake in people who exercise regularly in gyms in the city of Belo Horizonte, Brazil, and discuss the influencing factors on its ingestion. Methods: A total of 1102 enrolled subjects who exercised in 50 gyms throughout the city were part of this cross-sectional study. Men and women were recruited and all subjects were at least 18 y old. Participants were asked to complete written questionnaires about their use of supplements. Data were collected over a period of 4 mo. Descriptive statistics and chi-square tests were performed. Results: The intake of nutritional supplements was reported by 36.8% of participants. The highest intake was in men (44.6%). Five products were consumed almost daily: those rich in proteins and amino acids (58%), isotonic drinks (32%), those rich in carbohydrates (23%), natural/phytotherapeutic (20%), and multivitamin/mineral supplements (19%). Most people (55%) reported using nutritional supplements without any specialized professional guidance and based primarily on self-prescription. Individuals younger than 30 y, mainly men (odds ratio 3.28, 95% confidence interval 2.06-5.20, P < 0.01), took supplements rich in proteins (odds ratio 2.73, 95% confidence interval 1.26-5.94, P < 0.05). In contrast, older participants reported taking supplements rich in multivitamin/minerals and natural/phytotherapeutic agents (odds ratio 5.52, 95% confidence interval 2.76-11.06, P < 0.01). Conclusion: Our results show that supplement intake in people exercising in gyms is high and is usually self-prescribed. We emphasize that the use of dietary supplements must be always done under the supervision of a specialist (physician or nutritionist). (C) 2010 Elsevier Inc. All rights reserved.