IntroductionChronic-plaque psoriasis is a chronic inflammatory dermatological disease. Obesity comorbidities, including non-alcoholic fatty liver disease, are highly prevalent in patients with chronic-plaque psoriasis. Recently, weight loss has been a highly recommended intervention to improve the severity of psoriatic symptoms, psoriasis-induced chronic systemic inflammation, psoriasis-associated cardiovascular risk factors, quality of life, and the efficacy of anti-psoriatic drugs. This study was designed to assess the effect of a 12-week low-calorie-diet intervention on aspartate transaminase, psoriasis severity (assessed via Psoriasis Area and Severity Index – PASI), alanine transaminase, quality of life (assessed via Dermatology Life Quality Index – DLQI), triglycerides, waist circumference (WC), and body mass index (BMI) in class I obese men with chronic-plaque and non-alcoholic fatty liver disease.Material and methodsSixty men with age ≥ 18 years with class I obesity and with chronic plaque psoriasis and non-alcoholic fatty liver disease were included in the study. All participants were randomly assigned to one of two groups: the first group as the low-calorie-diet group (30 men received immunosuppressive drugs, followed a low-calorie diet, and increased their energy expenditure through a daily 15,000-step outdoor walking program for 12 weeks) and the second as the control group (30 men received immunosuppressive drugs only). The primary outcome consisted of the results of the area and severity index. Weight, BMI, WC, laboratory results such as triglycerides, liver enzymes (alanine transaminase and aspartate transaminase) as well as DLQI were considered as secondary outcomes.ResultsWhile no significant improvements were achieved in the measured variables of the control group, the low-calorie-diet group demonstrated significant improvement in all the measured variables.ConclusionsThe results of the present study confirmed that 12-week low-calorie-diet intervention controls BMI, increases the response of psoriasis to pharmacological agents and improves the quality of life. Diet interventions significantly control the elevated hepatic enzymes (aspartate and alanine transaminases) and triglycerides in male patients with chronic-plaque psoriasis and non-alcoholic fatty liver dis-ease.