Consistent with these findings, a recent study reported that serum FGF21 levels can predict NAFLD improvement in patients with a very low caloric KD (32); fatty liver is also improved with increased tissue FGF21 mRNA expression levels in intermittent KD [abstract: diabetes 2020 Jun; 69 (Supplement 1):1957-P]. The gene discussed is FGF21; the disease is metabolic dysfunction-associated steatotic liver disease.