Physical activity, diet and gene–environment interactions in relation to body mass index and waist circumference: The Swedish Young Male Twins Study

• Published in: Public health nutrition Vol. 9; no. 7; pp. 851 - 858
• Main Authors: Karnehed, Nina, Tynelius, Per, Heitman, Berit L, Rasmussen, Finn
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.10.2006
• Subjects: Adult; Body Mass Index; Body weight; Cohort Studies; Diet; Diet Surveys; Dietary fiber; Dietary Fiber - administration & dosage; eating habits; Epidemiology; Exercise; Exercise - physiology; Feeding Behavior; Genetic Predisposition to Disease; Gene–environment interaction; genotype-environment interaction; Genotype-environment interactions; Health care; human genetics; Humans; Linear Models; Male; Medicin och hälsovetenskap; men; Nutrition research; Obesity; Obesity - epidemiology; Obesity - genetics; Physical activity; Physical fitness; Public health; Questionnaires; Surveys and Questionnaires; Sweden; Swedish Young Male Twins Study; Twins; Twins, Dizygotic; Twins, Monozygotic; Variables; Waist circumference; Waist-Hip Ratio; Weight Gain - genetics; Young adults; Sweden; Waist circumference; Gene–environment interaction; Physical activity; Diet; Twins; Body weight
• ISSN: 1368-9800; 1475-2727
• DOI: 10.1017/PHN2005926

The aim of the present study was to examine the relationships between genetic susceptibility to obesity, physical activity (PA), dietary fibre, sugar and fat intakes and 4-year changes in body mass index (BMI) and attained waist circumference (WC) in a cohort of 287 monozygotic and 189 dizygotic young adult male twin pairs. Increased knowledge about interactions between genes and environment may provide insight into why some individuals are more prone to obesity than others. Information about PA, BMI, dietary habits, WC and potential confounders was collected by questionnaire in 1998 and 2002. The cohort data were analysed by mixed linear models. Twins with low PA attained larger WC than twins with high PA (difference 2.5 cm; 95% confidence interval (CI) 1.3, 3.6). The twins with the lowest fibre intake were found to have attained the highest WC and to have increased most in BMI (difference between highest and lowest fibre intakes: 1.6 cm, 95% CI 0.4, 2.9 and 0.45 kg m(-2), 95% CI 0.15, 0.76, respectively). Furthermore, our results suggested the presence of interactions so that twins with genetic susceptibility to obesity were more prone to have larger WC if sedentary than twins without genetic susceptibility. PA and a diet rich in fibre may be protective against weight gain among younger adult men. An interaction between PA, genes and attained WC is a novel finding which needs confirmation by other studies.