Adults who reported high levels of physical activity combined with low leisure time spent sitting were at a much lower risk for incident obesity after 5 years….
The researchers wrote, "The protective effects of moderate-to-vigorous physical activity and low leisure-time sitting against developing obesity and metabolic risk factor clustering are strongest when viewed in combination." "The interaction observed supports the notion that both high levels of physical activity and low levels of leisure-time sitting may be required to substantially reduce the risk of developing obesity. Associations with developing metabolic risk factor clustering were less clear. Intervention studies are needed to examine whether adverse metabolic changes in the form of obesity and metabolic risk factor clustering are best prevented by improving levels of both physical activity and leisure-time sitting."
Joshua A. Bell, MD, of the department of epidemiology and public health, University College London, and colleagues looked at data from the 3,670 participants (73% male; mean age, 55.5 years) in the Whitehall II cohort study who completed the questionnaire regarding their activity levels and followed up at 5- and 10-year increments with data on BMI and metabolic risk factors.
At 5 years, incident obesity was at 4.8% in the high activity group vs. 8% in the low activity group (P<.05); at 10 years, they were 6.9% and 11.9%, respectively (P<.05).
Being classified as intermediate or high activity level equated to an OR of 0.66 (95% CI, 0.47-0.91) and 0.67 (95% CI, 0.48-0.95), respectively, for incident obesity. These significant differences did not extend to the leisure groups.
When looked at in combination, though, high physical activity and low leisure-time sitting was associated with the lowest OR for incident obesity at 5 years (OR=0.23; 95% CI, 0.1-0.57) and 10 years (OR=0.47; 95% CI, 0.24-0.91) in minimally adjusted models. The ORs held similarly in the multivariable-adjusted models.
In looking at metabolic risk through multivariable adjusted models, the combination with the lowest OR of developing risk was the intermediate physical activity and intermediate leisure-time sitting at 5 years (OR=0.53; 95% CI, 0.36-0.78) and 10 years (OR=0.53; 95% CI, 0.36-0.77).
"Our findings on incident metabolic risk factor clustering did not follow a pattern of additive interaction or dose-response. The greatest reduction in risk observed for intermediate levels of physical activity and leisure-time sitting was unexpected and suggests that moderate amounts of both moderate-to-vigorous physical activity and leisure-time sitting may be sufficient to protect against developing metabolic risk factor clustering over time," researchers wrote.
- Both high levels of physical activity and low levels of leisure-time sitting may be required to substantially reduce the risk of developing obesity.
- Moderate amounts of both moderate-to-vigorous physical activity and leisure-time sitting may be sufficient to protect against developing metabolic risk factor.
Bell JA. Diabetologia. 2014;doi:10.1007/s00125-014-3323-8.