The outbreak of COVID-19 sparked a massive movement among the world's people to control this dangerous and unknown disease. So many nutritionists have made many medical recommendations to control this disease by using special nutrients. In this regard, we decided to examine the effect of two nutrients, protein and fat, which are the main ingredient in many nutrients, on the rate of death and recovery of patients covid-19. Available data from 170 countries worldwide have been examined to discover this effect. Linear and non-linear relationships and the correlation coefficient between response variables and different nutrients have been calculated and analyzed in detail. According to the results, these two elements cannot be considered influential in predicting the current rate with high reliability. Protein and fat have a high nutritional value and play an essential role in human health, but the amount of this need for humans is different, which in turn contradicts the results obtained from patients. Although correlation coefficients are not high, the existence of this correlation still requires further studies in this field. We have also used models such as Decision tree, Rule introduction, and Naive Bayes in our research to predict future results, which will give us an understanding of the results obtained.