###### Abstract  
Clinical Decision Support Systems (CDSSs) facilitate evidence-based clinical decision making for health professionals. Few studies have applied such systems enabling distance monitoring in the COVID-19 epidemic, especially in a hospital setting. The purpose of the present work was to assess the clinical efficacy of CDSS-assisted dietary services at a general hospital for patients intending to lose weight during the COVID-19 pandemic. Thirty-nine patients (28 men, 71.8%) comprised the intervention group and 21 patients (four men, 16%) of the control group. After a 3-month CDSS intervention, reductions in both body weight (mean \(\pm\) standard deviation (SD): 95.5 \(\pm\) 21.8 vs. 90.6 \(\pm\) 19.9 kg, \(p\) < 0.001) and body mass index (BMI) (median, interquartile range (IQR): 35.2, 28.4-37.5 vs. 33.2, 27.4-35.4 kg/m\({}^{2}\), \(p\) < 0.001) were observed. Beneficial effects were also recorded for total body fat (44.9 \(\pm\) 11.3 vs. 41.9 \(\pm\) 10.5%, \(p\) < 0.001), glycated hemoglobin (5.26 \(\pm\) 0.55 vs. 4.97 \(\pm\) 0.41%, \(p\) = 0.017) (mean \(\pm\) SD) and triglycerides (137, 115-152 vs. 130, 108-160 mg/dL, \(p\) = 0.005) (medians, IQR). Lean tissue was borderline decreased (25.4, 21.7-29.1 vs. 24.6, 21.8-27.9 kg, \(p\) = 0.050). No changes were documented in the control group. In multivariate linear regression models, serum triglycerides were inversely associated with % absolute weight loss (B = \(-\)0.018, standard error (SE) = 0.009, \(p\) = 0.050) in the CDSS intervention group. In women, a principal component analysis-derived pattern characterized by high BMI/lean tissue was positively related to % absolute weight loss (B = 20.415, SE = 0.717, \(p\) = 0.028). In conclusion, a short-term CDSS-facilitated intervention beneficially affected weight loss and other cardiovascular risk factors.  
clinical decision support system; CDSS; weight loss; COVID-19; nutrition intervention; Mediterranean diet +
Footnote †: journal: Medicalhealth professionals to conduct clinical research as well as to assess the improvement in patients with long-term nutritional care [1]. Indeed, the use of structured records and the incorporation of alerts/reminders have been shown to enhance the quality of medical records and provision of evidence-based care adherent to guidelines [6].  
During the COVID-19 era in Greece, certified dietitian and nutritionist services were restricted during certain quarantine periods (between March and June of 2020), due to state measures to control the spread of COVID-19. Similar measures were also in force for hospital outpatients while the health system was \"under pressure\". In parallel, good nutritional status and obesity prevention was of outmost importance for COVID-19 prevention and management [7; 8]. Hospital dietitians took care of hospitalized patients, and the special needs of whom were covered via menu modifications [9] and oral nutritional supplements [10]. During this difficult time, the use of electronic medical records [11] and tele-health were recommended to provide and monitor nutritional care [7]. Within this scope, the CDSS developed by our group, named Nutrinet(r), aimed to provide distance lifestyle advice while avoiding visits to healthcare providers and minimizing the risk of COVID-19 infection [3]. The clinical efficacy of the CDSS used in the present study was recently demonstrated in patients with breast cancer [4], multiple sclerosis [12] and rheumatoid arthritis [13], as well as pregnant women [14]. Several programs based on tele-health and remote consultations were developed to assist patients with obesity during weight loss, especially during COVID-19 [15; 16; 17]. However, to our knowledge, there is no study using CDSS in a hospital setting to enable distance counseling and monitoring of overweight and obese patients.  
The purpose of the present work was to assess the application and clinical efficacy of CDSS (Nutrinet(r))-assisted dietary services for patients at a general hospital who were intending to lose weight during the COVID-19 era.