Can You be Skinny and Still Have Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease among people in developed countries. In fact, nearly 1 in 3 adults and 1 in 10 children in the United States has it. Though the exact cause of NAFLD is unknown, being overweight or obese with a high amount of abdominal fat is the main risk factor for NAFLD.

Other risk factors are:

• high blood pressure, high cholesterol or diabetes
• being a postmenopausal woman
• being of Hispanic or Asian descent
• obstructive sleep apnea
• metabolic syndrome

Despite obesity with excess belly fat being the number one risk factor, being skinny does not completely eliminate the risk of getting nonalcoholic fatty liver disease, or NAFLD. One can be lean and still have many serious, chronic and unhealthful conditions, including the accumulation of fat deposits in the cells of the liver that causes NAFLD. 

Skinny people can have fatty liver disease 

Though obesity is the main risk factor for NAFLD, It’s estimated that around 7% to 10% of people with NAFLD are considered lean. Like obese people with NAFLD, lean people with NAFLD often, but not always, also have metabolic syndrome. Metabolic syndrome is a cluster of conditions that greatly raise the risk for cardiovascular disease. These conditions include high blood pressure, insulin resistance, elevated LDL cholesterol and elevated triglycerides. It is unknown whether having NAFLD puts people at risk for metabolic conditions, or vice versa. But the combination of conditions is the most serious health threat for skinny people with NAFLD.

A recent study looked at the prevalence of NAFLD in more than 6,000 lean and obese adult men and women of multiple ethnicities. Lean people were defined as those with a body mass index (BMI) of 25 or lower and a waist circumference of 90 centimeters or less for men or 80 centimeters or less for women. Obese people were defined as those with a BMI over 30 and a waist circumference over 102 centimeters for men or over 88 centimeters for women. 

In the lean group, men and women were equally likely to have NAFLD. And there was no consistent pattern for race or ethnicity among lean people with NAFLD. Conversely, obese people with NAFLD are largely of Mexican or Asian heritage. 

But, of the lean people in the study with NAFLD, nearly 75% also had metabolic conditions which put them at high risk for cardiovascular disease. Of the nearly 25% of lean people with NAFLD who did not have other metabolic conditions, the risk of premature death by cardiovascular disease or other non-accidental causes was very low, practically the same as the general healthy population. 

This study shows that, among skinny people with NAFLD, the more serious health threat is also having a metabolic condition.

Whether skinny or obese, and whether you have an adjoining metabolic condition or not, the best treatment for NAFLD is to make some changes to your diet. For lean people with NAFLD, the first remedy should be to eat fewer simple carbohydrate foods while eating more plant-based foods high in fiber. Simple carbohydrates, including processed grains, high fructose syrups and other added sugars are associated with insulin resistance and increased fatty deposits on the liver. 

Read more about How to Eat Well for Nonalcoholic Fatty Liver Disease.