Nearly 100 million Americans face this diet-related condition—here's what to do to avoid it.

Fatty liver disease, once most commonly associated with alcoholism, has become a significant issue for Americans: An estimated 100 million people have developed fatty liver disease, which causes the liver to swell with dangerous levels of fat deposits. And nearly seven million of those affected are under 18—which is even more dire, since fatty liver disease significantly raises the risk of Type 2 diabetes and heart disease among other conditions.

But new research finds that overweight and obese adolescents suffering from fatty liver disease were able to greatly reduce the amount of fat and inflammation within their livers by cutting out fruit juices, sugary sodas and soft drinks, and foods with lots of added sugars in their diet. The report, published in the Journal of the American Medical Association last month, provides more context on how Americans can reduce their risk for this disease, which has become prevalent over the last decade.

Medical professionals have long advised that overweight individuals drastically reduce sugar consumption as a weight loss strategy, but it may be even more crucial for working against fatty liver disease, which has virtually no detectable symptoms.

Nutritionist Brierley Horton, MS, RD, says that current medical guidelines say those with fatty liver disease should focus on a healthy, wholesome diet and an exercise regimen. But there's not a list of specific foods or rules, and highly processed foods contain added sugars that are much different than sugars occurring naturally in foods like fruit.

“The current standard of care is very similar to what we would recommend for any child that is overweight,” Dr. Miriam Vos, one of the authors behind the new study and a professor of pediatrics at the Emory University School of Medicine, told the New York Times. “Unfortunately, that general recommendation hasn’t improved the disease as much as we would like, and there are no large randomized trials looking at which diet is the best one for fatty liver.”

This particular study consisted of 40 children with an average age of 13 years old, with liver fat content ranging between 21 and 25 percent, which is more than four times the recommended amount. The children tried two different diets for eight weeks, with one group greatly reducing added sugar intake, and the other being told to continue eating as they had been. To ensure that the diet was being enforced, researchers asked the participants' families to follow the diet as well, mostly swapping in lower-sugar alternatives for common staples like bread, salad dressings, and yogurts.

The report notes that fruit juices and sodas were off limits for those on a special diet—they were replaced with water, milk, and other non-sugary drinks like iced tea. Families had the help of dietitians, who delivered non-restrictive meals that weren't tailored to lower calories or carbs, but were just low on sugar. The participants' sugar intake was less than 3 percent of their daily calories, which is a pretty strict intake given that the current recommendations from the World Health Organization only suggest keeping it to 10 percent.

Credit: Adobe Stock / Oksana Kuzmina

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After eight weeks, those on a special diet had gotten their added sugar intakes down to just 1 percent of their daily intake, compared to 9 percent in the control group. Their livers had transformed remarkably in that time: around 31 percent of the fat composition had been reduced, opposed to zero change in the control group. They also lost about 3 pounds during the test period.

“As a practicing hepatologist, I see children weekly with fatty liver, and I would love to see this kind of improvement in my patients,” Vos said. “The exciting part was not only did the fat go down, but their liver enzymes also improved. That suggests that they also got a reduction in inflammation.”

Horton says that those who are prediabetic or are overweight or obese should especially take notice of this study, given that fatty liver disease is so closely associated with the two.

"Nutritionists often recommend eliminating packaged foods, as it could help you eat leaner. But it seems that packaged, processed products and junk foods could be doing more than just sabotaging your diet," she said. "If you can reduce your risk for cardiovascular disease by focusing on reducing added sugar, which could help your health overall, then it should be your list of things to tackle in your diet.