Physical Activity Protects Against NAFLD, Study Suggests

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Researchers found the lowest prevalence of non-alcoholic fatty liver disease (NAFLD) in adults achieving greater than 60 minutes per week of vigorous physical activity, they wrote in the Journal of Gastroenterology and Hepatology.

In addition, the researchers at the School of Sport, Rehabilitation, and Exercise Sciences at the University of Essex in Essex, United Kingdom, discovered a stronger dose-response relationship existed between cardiorespiratory fitness (CRF) and NAFLD.

“Improving cardiorespiratory fitness as a potential therapeutic target for treatment and prevention of non-alcoholic fatty liver disease warrants further investigation,” they wrote.

The researchers examined physical activity and CRF rates because he prevalence of Guidelines for the long-term treatment of NAFLD focus on weight loss and dietary control, “and there is a lack of evidence regarding other positive lifestyle behaviors, including the adoption of increased PA and the role of CRF, which are both associated with improved cardiometabolic profiles,” they said.

NAFLD continues to increase in parallel with other conditions, including obesity and type 2 diabetes mellitus, they noted. In addition, a poor quality diet and over-reliance on saturated and trans-fats, processed meat, sugar-sweetened beverages, and fructose, are risk factors associated with NAFLD.


“Relatively small amounts of weight loss can lead to significant reductions in liver fat, improved cardiometabolic risk profiles factors, and enhanced longer-term health outcomes,” they wrote.

PA guidelines in the UK recommend that individuals should be aiming to achieve 150 minutes of moderate intensity PA, or 75 minutes of vigorous intensity PA per week. However, it is unclear whether PA intensity plays a role in the development of NAFLD.

“No previous studies have examined the associations between PA intensities and CRF in individuals with NAFLD,” the researchers wrote.

This study included healthy adults with no prior diagnosis of liver dysfunction. Non-alcoholic fatty liver disease prevalence was estimated based on fatty liver index scores.

The researchers then created categories of self-reported low, moderate, and vigorous physical activity. Participants completed an incremental treadmill test to estimate cardiorespiratory fitness, and data were subsequently separated into five groups.

Non-alcoholic fatty liver disease was prevalent in 28.3% of men and 6.5% of females the researchers’ sample of around 7,000 adults.

Logistic regression showed the relative odds of non-alcoholic fatty liver disease were 42% lower if the individuals maintained greater than 60 minutes per week of vigorous physical activity.

Moderate physical activity, however, did not reduce the odds of non-alcoholic liver disease.

In terms of CFR, the odds of developing NAFLD were 51% lower in the most fit group versus the least fit group.


Kerr CJ, Waterworth SP, et al. The associations between physical activity intensity, cardiorespiratory fitness, and non-alcoholic fatty liver disease. J Gastroenterol Hepatol. Published online August 24, 2021. doi: 10.1111/jgh.15672.