Leisure-time physical activity and intra-abdominal fat in young adulthood: A monozygotic co-twin control study.
To investigate differences in abdominal fat compartments between young adult monozygotic twin pairs discordant for leisure-time physical activity.



Ten young adult male monozygotic twin pairs (age range 32-36 years) discordant for leisure-time physical activity during the past 3 years were systematically selected from a population-based Finnish twin cohort. Magnetic resonance image at the level of the L2-L3 intervertebral disc was used to predict intra-abdominal and subcutaneous abdominal fat masses. Dietary intake was assessed with a 4-day food diary.



Inactive twins had 31% more intra-abdominal fat than their active co-twins (mean difference 0.52 kg, 95% CI 0.12 to 0.91, P = 0.016), whereas the difference in subcutaneous abdominal fat was only 13% (P = 0.21) and 3% in body mass index (P = 0.28). Intraperitoneal fat mass was 41% higher among inactive twins compared to their active co-twins (mean difference 0.41 kg, 95% CI 0.11 to 0.70, P = 0.012). Dietary intake did not differ between co-twins.



A lower level of physical activity is related to greater accumulation of intra-abdominal fat among healthy adult males in their mid-30s. The findings highlight the importance of leisure-time physical activity independent of genes and diet in the prevention of intra-abdominal fat accumulation from early adulthood onward.
Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Mirva
M
Rottensteiner
Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.|Turku PET Centre, University of Turku, Turku, Finland.
Tuija
T
Leskinen
Institute of Public Health and Clinical Nutrition, Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
Elina
E
Järvelä-Reijonen
School of Business and Services Management, JAMK University of Applied Sciences, Jyväskylä, Finland.
Karoliina
K
Väisänen
Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.|Department of Public Health and Department of Social Research, University of Helsinki, Helsinki, Finland.
Sari
S
Aaltonen
Department of Public Health, and Institute for Molecular Medicine, University of Helsinki, Finland.|Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
Jaakko
J
Kaprio
Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Urho M
UM
Kujala
D000328:Adult; D015930:Diet Records; D015444:Exercise; D005247:Feeding Behavior; D005387:Finland; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging; D007899:Leisure Activities; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity; D056128:Obesity, Abdominal / Q000209:etiology / Q000517:prevention & control; D050507:Subcutaneous Fat, Abdominal / Q000000981:diagnostic imaging; D014430:Twins, Monozygotic