Discussion

The present research aimed to explore the nutritional knowledge, attitude and behaviour associated with COVID-19. The overall results revealed that the majority of participants were male, married, holding a diploma or higher degree, average economic status and employed.

The mean score for the participants’ nutritional knowledge was above the average. Though there have been several studies conducted in other countries such as China^{(Reference Zhong, Luo and Li2)}, Thailand^{(Reference Srichan, Apidechkul and Tamornpark9)}, USA^{(Reference Clements10)} and Jordan^{(Reference Alzoubi, Alnawaiseh and Al-Mnayyis11)}, no similar research was found with a focus on nutrition regarding COVID-19 at the time of the present research to compare the results with. Regarding knowledge, 88·3 % of the participants perceived food as a way of transmitting the disease. In some other work of research in Singapore, similarly, the participants often mentioned food as one way of transmitting the disease^{(Reference Lim, Lim and Tan12)}. In two studies conducted in China and USA, respectively, 91 % and 54 % of the participants answered correctly to the item: ‘Eating the mean of wild animals can cause the disease’^{(Reference Zhong, Luo and Li2,Reference Clements10)} . This item, in the present research, belonged to the attitude section and 42 % of the participants agreed while the rest either disagreed or had no opinion. There was a significant difference between the percentages of correct answers Chinese participants gave and that of US and Iranian, which is probably explained by the different diets common in these countries. The origin of this viral disease, epidemiologically speaking, was primarily the whole sale of sea food in China and wild animals were the main source of the disease^{(Reference Hou, Lin and Lu13)}. Infected animals and consuming contaminated food are probably the main source of viral infections⁽⁸⁾. Besides implementing the quarantine, closing animal markets in China was a key measure taken in China to prevent the epidemic of the virus. Purchasing healthy food materials and changing the traditional habit of eating wild animals (and their products) have been recommended as a preventive behaviour^{(Reference Ahmadiara5,Reference Hou, Lin and Lu13)} .

Concerning the other knowledge-related items associated with COVID-19, the majority of answers provided corresponded to the existing knowledge at the time of the research and the recommendations by WHO and educational programmes broadcast on Iran TV. Inadequate food materials and vitamins such as A, C and D and weakened immune system would raise the chances of the disease^{(Reference Taghdir, Sepandi and Abbaszadeh14,Reference Zhang and Liu15)} . Consuming vegetables and salad and fruits containing vitamin C, carrot, pumpkin and onion in the main meals, proteins such as egg and avoiding fast foods, raw or medium-cooked food, avoiding eating at unhealthy places and washing fruits and vegetables are commonly recommended to better prevent the disease^{(Reference Zhang and Liu15,Reference Saul16)} . Moreover, avoiding high doses of vitamin and mineral supplementary and overconsumption of such food materials as ginger or garlic are recommended that can affect metabolism and disrupt absorption and effect of drugs^{(17,Reference Ross, Caballero and Cousins18)} . Eating fresh food, drinking enough water and liquid, balanced consumption of oil and less salt and sugar, avoiding eating at crowded places outside home and consultation in the case of affliction with the disease are among the recommendations made by WHO for adult nutrition in COVID-19 crisis⁽¹⁹⁾ that majority of participants answered correctly.

Concerning attitude, the majority of participants disagreed with these statement that eating the meat of wild animals forbidden in Islam led to the disease. Though this item was not asked from the participants, as COVID-19 is introduced as a viral respiratory disease, there are chances that the participants considered this disease primarily viral. Similarly, Butler and Barrientos in their research drew attention to the prevalence of the disease among diabetic and obese patients. This shows that the eating style especially Western eating style which involves saturated oil, high sugar and low fibre can weaken the immune system and reduce B and T lymphocytes. However, healthy fresh food with its anti-inflammatory effect even in the obese can help to prevent the disease and improve their conditions. Therefore, a healthy life style especially one marked by consuming more fibre and unsaturated oil and antioxidants and refraining from foods containing high levels of sugar and unsaturated oil is recommended to strengthen the immune system^{(Reference Butler and Barrientos6)}. Zhang and Liu, in their research, recommended the use of foods rich in vitamins A, B, C, D and E as a public intervention to strengthen the general system to prevent and treat the disease^{(Reference Zhang and Liu15)}. Some other research in Nigeria showed that about 11 % of the participants perceived consuming garlic, ginger and certain herbs and soups as effective ways of preventing the disease^{(Reference Ali and Alharbi20)}.

As for nutritional behaviours associated with COVID-19, participants showed that they often abided by the recommendations made by WHO broadcast in national TV. These included washing hands, cooking foods, washing and consuming fruits and vegetables and avoiding eating out in crowded places, consuming prepacked foods, consuming water, garlic and ginger. As study conducted in Jordan showed that university students ate garlic, ginger syrup and honey to prevent the disease. The results revealed no statistically significant difference between medical and non-medical university students^{(Reference Alzoubi, Alnawaiseh and Al-Mnayyis11)}. Similarly, in the present research, no statistically significant divergence was found in terms of knowledge and attitude between university students and others. However, women and more specifically housewives showed healthier nutritional behaviour based on updated knowledge of nutrition at the time of COVID-19 than others. As women have long played a key role in promoting and supporting food consumption in family, they also play a key role through cooking healthy food to promote healthy behaviours in family. Thus, this result is desirable considering the probable effect of healthy nutrition on preventing COVID-19. Knowledge and level of education on the one hand and behaviour and economic status on the other showed to be correlated. A similar correlation was found in the study in American context among the black who were also less educated and had also lower income^{(Reference Clements10)}.