High fiber intake and increased exercise may reduce abdominal fat
MedWire News: Increased soluble fiber intake and participation in vigorous activity are associated with a decreased rate of accumulated visceral fat, suggests an analysis of the IRAS Family Study.
Previous studies have found that reductions in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) can lead to decreased risk for cardiovascular disease and Type 2 diabetes, independent of total body fat.
To examine whether lifestyle factors, such as diet and frequency of exercise, were associated with a 5-year change in abdominal fat, the researchers analyzed data for over 1000 participants (339 African Americans and 775 Hispanic Americans) of the Insulin Resistance and Atherosclerosis (IRAS) Family Study.
Dietary intake was assessed using a food frequency questionnaire and physical activity was documented by self-report and a 1-year recall instrument. VAT and SAT were measured by computed tomography at baseline and after 5 years.
Kristen Hairston (Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA) and co-workers found that soluble fiber intake and participation in vigorous exercise (defined as activities that make you sweat, increase your heart rate, or increase your breathing rate) were associated with a significant reduction in VAT, independent of body mass index.
The team says that for every 10 g increase in soluble fiber eaten per day, VAT was reduced by 3.7%, suggesting that increased soluble fiber may be involved in slowing the rate of VAT accumulation. Soluble fiber intake was not associated with SAT accumulation, however.
Individuals reporting vigorous activity "sometimes" - between once per month and four times per week - had a 7.4% and 3.6% reduced VAT and SAT accumulation, respectively, compared with those who reported participating in vigorous activity "rarely" or "never."
"Our study is valuable because it provides specific information on how dietary fiber, specifically soluble fiber, may affect weight accumulation, specifically through the abdominal fat depots," write Hairston et al in the journal Obesity.
They conclude: "As we continue to explore the reasons for the rapidly escalating rates of obesity and diabetes in young people, particularly ethnic minority groups, interventions that increase the intake of dietary fiber may be a possible approach for prevention."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Nikki Withers