Nearly 1/3 of Americans (about 100 million people) have non-alcoholic fatty liver disease (NAFLD). People with NAFLD are usually obese, have insulin resistance and/or metabolic syndrome. While people with NAFLD are often told to lose weight as a way to decrease fat that surrounds the liver, a new study shows that exercise alone can significantly reduce those levels.
Along with other changes in lifestyle habits, exercise can of course, also contribute to weight loss. The new study, published in American Journal of Gastroenterology shares promising evidence that even if the desired weight loss isn’t yet reached through diet alone, just exercising can help reduce the factors that contribute to NAFLD. Exercise of about 150 minutes each week (that’s only about 20 minutes a day!) at a moderate intensity significantly reduced liver fat in patients, the new meta-analysis showed. This level of exercise is also the recommended amount of activity for adults by the CDC.
For this study, the researchers considered a 30% relative reduction in liver fat- measured by MRI scans- to be meaningful improvement. Then, they reviewed 14 randomized controlled trials with a total of 551 people with NAFLD.
Then they determined the optimal dose of exercise, finding that 39% of patients who were exercised at moderate intensity for 150 minutes per week or more achieved a significant treatment response compared to 26% of those who were exercising less than that.
Moderate intensity exercise was defined as is within a variety of guidelines- the Mayo Clinic shares:
- Your breathing quickens, but you’re not out of breath.
- You develop a light sweat after about 10 minutes of activity.
- You can carry on a conversation, but you can’t sing.
The investigators found that, independent of weight loss, exercise was 3.5 times more likely to achieve this 30% reduction in liver fat compared to standard care.
It isn’t new information that exercise and improving physical fitness can battle risk factors that contribute to NAFLD, including:
- Obesity: Obesity involves low-grade inflammation that may promote liver fat storage. It’s estimated that 30–90% of obese adults have NAFLD, and it’s increasing in children due to the childhood obesity epidemic.
- Excess belly fat: Normal-weight people may develop fatty liver if they are “viscerally obese,” meaning they carry too much fat around the waist.
- Insulin resistance: Insulin resistance and high insulin levels have been shown to increase liver fat storage in people with type 2 diabetes and metabolic syndrome.
But there hadn’t yet been a specific quantity or intensity of exercise defined as what was necessary to specifically reduce the fat that surrounded the liver in people living with NAFLD. Without prescription medications currently available to address NAFLD, diet (reducing or stopping fats, triglycerides, and sugar intake) and weight loss have been the primary avenues to address the illness and prevent progression to more serious stages.
Adding exercise to the list of tools that people can utilize is significant, and along with continuing to modify diet to achieve weight loss, provides people another avenue to address NAFLD.