A diet high in animal protein is associated with a higher risk of non-alcoholic fatty liver disease (NAFLD), a condition in which fat builds up in the liver, in overweight people, says a study.

Non-alcoholic fatty liver disease is a major health concern as it can lead to permanent scarring (cirrhosis) and subsequently to cancer and malfunction of the liver. This may result in life-threatening complications for which a liver transplant is needed. "A healthy lifestyle is the cornerstone of treatment in patients with NAFLD, but specific dietary recommendations are lacking," said led author of the study Louise Alferink from the Erasmus Medical Centre, Rotterdam, The Netherlands.

"The results from this study demonstrate that animal protein is associated with NAFLD in overweight elderly people," Alferink said. These findings presented at The International Liver Congress 2017 in Amsterdam also showed that fructose consumption per se might not be as harmful as previously assumed.

A total of 3,440 people were included in the study of whom 30 per cent were lean and 70 per cent were overweight (body mass index [BMI] of 25 kg/ square metre or greater). The average age was 71 years and NAFLD, as assessed by abdominal ultrasound, was present in 35 per cent of the participants.

Macronutrient intake was recorded using an externally validated 389-item food frequency questionnaire and analysed in quartiles using the nutrition density method (energy percentage). Furthermore, analyses were stratified for BMI to account for BMI-related differences in eating habits and dietary measurement errors. Significant associations between macronutrients and NAFLD were found predominantly in overweight individuals. The results showed that total protein was associated with higher odds of NAFLD and this association was mainly driven by animal protein.