Risk is highest for those who are obese or who have diabetes, investigator from Keck Medicine and the University of Southern California indicate.
Eating fast food is associated with nonalcoholic fatty liver disease, a potentially life-threatening condition where fat builds up in the liver, according to the results of a study published in Clinical Gastroenterology and Hepatology.
Investigators from Keck Medicine at the University of Southern California found that individuals who are obese or who have diabetes and consume 20% or more of their daily calories from fast food have an increased level of fat in their liver compared with those who consume less or no fast food.
Additionally, they found that the general population has moderate increases of liver fat when one-fifth or more of their diet consists of fast food.
“Healthy livers contain a small amount of fat, usually less than 5%, and even a moderate increase in fat can lead to nonalcoholic fatty liver disease,” Ani Kardashian, MD, a hepatologist with Keck Medicine, said in a statement. “The severe rise in liver fat in those with obesity or diabetes is especially striking, and probably due to the fact that these conditions cause a greater susceptibility for fat to build up in the liver.”
Previous research results show a link between fast food and diabetes and obesity, but the results of this study are the first to show the negative impact of fast food on the liver, according to Kardashian.
The results also showed that even a relatively modest amount of fast food can hurt the liver.
Even 1 meal at a fast-food restaurant can be a risk to individuals’ livers if the meal equals at least one-fifth of their daily calorie intake, Kardashian said.
Investigators analyzed the most recent data from the 2017 to 2019 National Health and Nutrition Examination Survey, the largest national annual nutritional survey, to help demine the impact of fast food on liver steatosis. They defined fast food as meals, including pizza, from either a drive-through restaurant or a restaurant without a wait staff.
Additionally, investigators evaluated the fatty liver measurement of approximately 4000 individuals whose fatty liver measurements were included in the survey and compared the measurements with fast-food consumption.
Of those in the survey, 52% consumed some fast food. Of those, 29% consumed one-fifth or more daily calories from fast food. Investigators found that just 29% experienced a rise in liver fat levels.
Furthermore, the association between liver steatosis and a 20% diet of fast food was consistent between the general population and those who had diabetes or were obese, even after the data was adjusted for other factors, including age, alcohol use, ethnicity, physical activity, race, and sex.
“Our findings are particularly alarming, as fast-food consumption has gone up in the last 50 years, regardless of socioeconomic status,” Kardashian said.
“We’ve also seen a substantial surge in fast-food dining during the COVID-19 pandemic, which is probably related to the decline in full-service restaurant dining and rising rates of food insecurity. We worry that the number of those with fatty livers has gone up even more since the time of the survey,” Kardashian said.
Investigators hope that these results encourage physicians to offer patients more nutrition education, especially who are obese or who have diabetes and are at a higher risk of developing fatty liver, because of fast food.
Consumption of fast food linked to liver disease. EurekAlert. News release. January 10, 2023. Accessed January 10, 2023. https://www.eurekalert.org/news-releases/976046