It’s well known that excessive sitting and sedentary behaviour is not good for us. It’s even been compared to smoking in terms of the negative effect it can have on our health. And now researchers have found new evidence to suggest that longer periods of sedentary time (defined as any sitting/reclining activity with low energy expenditure) may be associated with the amount of fat deposited around internal organs.
The research involved 124 participants and the aim was to examine the associations between objectively measured sedentary time (total time spent sitting/reclining and prolonged bouts), breaks in sedentary time, and MRI-assessed body composition in a population at a high risk of type II diabetes, and to determine whether associations are mediated by the recommended levels of moderate to vigorous physical activity (MVPA).
At a 12-month follow-up measurement, participants were invited to undergo an MRI scan in addition to other study assessments. Through this scan, liver, visceral, subcutaneous and total abdominal fat (includes liver, subcutaneous and visceral fat) was quantified.
Following adjustment for age, sex, ethnicity, social deprivation, smoking status, lipid-lowering medication, randomisation arm, dietary fat intake, and time the accelerometer was worn, each 60 minutes of sedentary time was associated with 1.74 L higher total abdominal fat, 0.62 L higher visceral fat, 1.14 L higher subcutaneous fat and 1.86% higher liver fat. When results were stratified by MVPA (active vs inactive), sedentary time was associated with greater liver, visceral and total abdominal fat in the inactive group only.
According to the authors of the study, the results demonstrate that the associations between sedentary time and liver, visceral and total abdominal fat are stronger in those who do not reach the current exercise recommendations for health (< 150min/wk), whereas no significant associations were observed in the active (> 150min/wk) cohort. For individuals at high risk of type II diabetes, the results show that sedentary time is detrimentally associated with liver, visceral and total abdominal fat, independent of important confounders (including MVPA).