Hidden sugar hurts your liver as much as your waistline.

If you don’t drink alcohol you might think you don’t have to worry about liver health. Well, think again, because the amount of sugar in our diet—sugar we are aware of and sugar that’s just added to a lot of what we eat— also puts us as risk for liver damage from non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH). 

Non-alcoholic fatty liver disease (NAFLD) occurs when excess fat builds up in the liver. Non-alcoholic steatohepatitis (NASH), a more advanced form of NAFLD, occurs when scarring builds up as the liver tries to heal itself. That scarring causes the liver to lose blood flow.

Physiologically, these conditions result because the liver processes fructose—which is very common in the American diet—and alcohol in a similar fashion: The fructose hits your liver. Your liver says, “Do I need this?” If the answer is “No.” So your liver turns the sugar into fat, and deposits some around your waist. (If your waist is bigger than your hips, that’s a sign you might be at risk.) But some fat also stays in your liver, leading to the development of NAFLD, and, if this condition persists, NASH.

Laura A. Schmidt, PhD,  a professor of health policy in the School of Medicine at the University of California at San Francisco, estimates that 31 percent of American adults and 13 percent of kids have NAFLD. “The average American is eating almost three times more sugar than they should be,” says Schmidt. “Imagine if the average American were drinking three times as much alcohol as they should. We’d be alarmed. We should be alarmed about this.”  

Others think these numbers are overblown. “Fatty liver disease is not a disease but a risk factor, a manifestation of being overweight,” says Druin Burch, MD, a physician at England’s University of Oxford Hospitals. “It can lead on to inflammation and scarring of the liver which are real diseases. Telling people that have a fatty liver is no different from telling them they have a fatty elbow or a fatty neck.”  

Whether you believe Schmidt or Burch, it’s still wise, for a variety of health reasons (including links to Alzheimer’s Disease) to monitor sugar consumption. “An adult woman should have no more that 6 teaspoons of added sugar—sugar not naturally occurring in fruits or vegetables—a day,” says Schmidt. “Men should have no more than 9 teaspoons.” 


  1. sugarscience.org
  2. Druin Burch, “The Invention of an Illness,” Slate.
  3. Laura A. Schmidt, UCSF
  4. “The Sugar and Alzheimer’s Connection,” Mother Jones