Nonalcoholic fatty liver disease often flies under the radar. The condition, a buildup of excess fat in the liver, typically causes no symptoms, so many people who have it don’t know they have it. But it’s one of the most common causes of liver disease in the United States. The National Institutes of Health estimates that about one in four adults have it, along with close to 10 percent of children ages 2 to 19. And if left untreated, it can lead to liver failure and other serious conditions, including heart disease and Type 2 diabetes.

While fatty liver is more common in people with obesity, you don’t have to be obese or even overweight to have the condition. That was the case with Dr. Sameer Murali’s family. 

“My family is pretty much average-weight people who are highly prone to getting fatty liver and Type 2 diabetes,” says Dr. Murali, an associate professor at McGovern Medical School at UTHealth Houston and an affiliated specialist in obesity medicine at Memorial Hermann. “Seeing so many people in my family get diabetes and die from complications of that disease, despite not being overweight, was part of why I got into obesity medicine.”

“You can also have obesity without having fatty liver,” he explains. “It boils down to the storage capacity of your body’s fat cells, which is largely genetically determined. Some people have fat cells that can only store a very small amount of fat, like the volume of a shot glass, while some can store a much larger amount, like a Big Gulp. People with the lower storage capacity are more likely to develop fatty liver even if they don’t look overweight.”

When your fat cells run out of room, your body starts putting the excess into other cells, including your muscles and vital organs.

“Fat cells are basically the savings account for the human body in terms of energy,” he says. “Fat is the long-term form of energy that gets stored away for times of scarcity. Your body doesn’t want to eliminate it. Just like if you won the lottery and you have $2 billion coming to you, you don’t want to chuck some of that in the bayou just because you can’t deposit it all in the bank. You’d find other places to keep it.”  

The problem with storing excess fat in the liver cells, muscle cells, or the cells of other organs is that it disrupts the normal function of those cells and can produce an inflammatory response, further damaging them.

“That inflammation then becomes scar tissue, and when there’s scarring inside the liver, it’s called cirrhosis,” Dr. Murali says. “Cirrhosis as a consequence of obesity is the same pathophysiology as when a person overconsumes alcohol. Today, the most common cause of fatty liver, cirrhosis and liver failure is obesity — it’s no longer alcohol consumption, as it once was.”

Routine lab tests that are a standard part of annual physicals, such as liver enzyme measures and platelet counts, can help a physician calculate a fibrosis risk score that indicates whether you’re at risk for scarring in your liver. If you do have the condition, treatment comes down to lifestyle changes; no medications have been approved to treat fatty liver. Losing at least 3 to 5 percent of your body weight can reduce fat in the liver, while losing 7 to 10 percent of your body weight can reduce liver inflammation and fibrosis, according to the NIH.

Weight loss is never easy, especially this time of year, but there are some healthy choices that can go a long way toward reducing excess fat, Dr. Murali says. One of the biggest is to avoid sugary drinks.

“The quickest way to make fat in your body is to drink sugar,” he says. “If you’re drinking sodas, sweet teas or juice, that’s literally the fastest way to build fat. Your glucose level goes sky high, your insulin level chases it, and your body can’t use all that energy all at once, so it starts making fat almost immediately. You drink orange juice and there’s almost no digestion needed; it goes straight into your bloodstream.”

Dr. Murali doesn’t recommend strict calorie restrictions or counting calories, which can be impractical for many people. Instead, he encourages people to be thoughtful about what they put on their plate. Over the holidays, that might mean less pie and more vegetables, and smaller portions overall.

“At every meal, especially lunch and dinner, half of what we’re eating should be vegetables,” he says. “They have a ton of fiber and not a lot of sugar.”

Finally, exercise is paramount — but that doesn’t have to mean joining a gym or starting a strenuous workout regimen. It can be as simple as walking more throughout the day.

“Even more than weight loss, physical activity is the most helpful in terms of health and longevity,” Dr. Murali says. “The easiest way to be more active is to find people to be active with you. People who live to be 100 aren’t doing workout videos alone in their basement; they incorporate physical activity into their everyday life.”

For more information, visit memorialhermann.org/services/conditions/chronic-liver-diseases.