Background: In several disease conditions, patients must inevitably be nourished by enteral feeding (EF). Though in many countries, commercial formulas are routinely used for EF, in Iran still home-made formulas are commonly employed as commercial formulas are not covered by insurance. This may pose patients to malnutrition and bring about further costs. The aim of this study was to evaluate the efficacy of EF commercial formulas in comparison with home-made formulas and thus to make further evidence for insurance policy-making Methods: Medline, Cochrane, Embass and Center for Review & Dissemination (CRD) as well as IranDoc and SID databases were searched. Keywords included formula, ICU, and enteral nutrition or tube feeding. No clinical trial study on the efficacy of EF formulas was found. Therefore, the compositions of available formulas and their cost-effectiveness were evaluated based on the clinical guidelines of scientific bodies such as American Society for Parenteral and Enteral Nutrition (ASPEN), European Society for Parenteral and Enteral Nutrition (ESPEN) and relative articles available in PubMed. In addition, the expert opinions were also taken into consideration. Results: Domestic commercial formulas seemed to less merit dietary recommended intakes, i.e. the amount of some nutrients were much higher, and some others were much lower than the recommended values. The amount of several micronutrients including vitamins B1, B6, C, D and K, as well as iron, calcium and magnesium were not sufficient to meet the body needs in most commercial formulas upon receiving 2000 kilocalories and less. Conclusion: Clinical studies on the efficacy of commercial formulas in comparison with home-made formulas are needed. Meanwhile, making suitable conditions for increasing the diversity of artificial nutrition products in the market would help clinical nutritionists to make better choices according to their patients conditions and to reduce the costs, as well.

Background This study aimed at reviewing effective food hygiene principles and dietary intakes to reinforce the immune system for prevention of corona virus disease 2019 (COVID-19). Methods The systematic literature search was performed in three databases from Jan. 2020 up to 10th July 2020. English articles that focused on nutrition, food, immunity and corona virus were searched. Systematic and narrative reviews were included. Results After evaluation of search papers, 27 relevant articles were used in this review. The importance of nutrients, phytochemicals, probiotics and some spices were highlighted for enhancing immunity during the COVID-19 pandemic. A healthy dietary pattern with proper energy intake provides sufficient nutrients. The unhealthy dietary pattern is linked with inflammation and risk factors related to high mortality in patients with severe COVID-19 infection. Different thermal procedures have been used for the inactivation of viruses. It is recommended not to consume raw or undercooked animal products. Conclusions It is critical to ensure that the nutritional needs of the population are met and sustained based on standards during a COVID-19 pandemic. Clear advice on adequate calorie intake and an optimal healthy diet to support the immune function should be provided. Good hygiene practices must be performed by everyone and done in the food industry.