Do ultra-processed foods cause fat to build up in the liver?

We looked at the evidence and found that ultra-processed foods—like sugary snacks, sodas, and fast food—may contribute to liver fat buildup. One reason is that these foods are often easy to overeat. They’re designed to be tasty and convenient, which can lead people to consume more calories than they realize. Also, the body absorbs these foods quickly, which may affect how the liver processes fat ¹.

Our current analysis shows the evidence leans toward a connection between ultra-processed foods and liver fat. However, we only have one assertion to base this on, even though it’s supported by 60 studies. We don’t yet know all the details—like how much of these foods it takes, or whether other lifestyle factors play a major role.

We don’t have enough evidence to say for sure that ultra-processed foods directly lead to fat in the liver in all people. But what we’ve reviewed so far points in that direction.

Practical takeaway: If you’re concerned about liver health, cutting back on ultra-processed foods like packaged snacks, sugary drinks, and fast food might be a helpful step—even if we’re still learning exactly why and how it matters.