The association between macronutrient intakes and coronavirus disease 2019 (COVID-19) in an Iranian population: applying a dynamical system model

AIMS: The possible role of lifestyle including diet on immunity led us to investigate the association between dietary macronutrient intake and COVID-19 in an Iranian population. METHODS: Dietary intakes were recorded in the first phase of the MASHAD cohort study (started in 2007), using a 24-h dietary recall. To determine the COVID-19 incidence, data from all PCR-positive patients in Mashhad were recorded between February 2020 and June 2022. Dietary macronutrients were included in the regression model, adjusting for age and sex. System dynamical models were also applied. RESULTS: The analysis included 1957 participants, including 193 COVID-19-positive patients. Dietary intakes of non-starch polysaccharides (NSP) and fiber were significantly lower in COVID-19 patients (P < 0.05). After adjusting for age and sex, starch and total sugar were significantly associated with COVID-19 infection ((OR = 1.0008, P = 0.001) and (OR = 1.0006, P = 0.026), respectively). There was also a significant association between dietary fiber intake and hospitalization (OR = 0.99, P = 0.018). In the dynamical system models, dietary intakes of cholesterol, polyunsaturated fatty acids (PUFA), and total sugar above 180.2 mg, 13.11 g, and 79.53 mg, respectively, were associated with an increased susceptibility to COVID-19 infection, while dietary fiber had a protective role. CONCLUSION: Dietary intake of starch and total sugars was associated with increased odds of COVID-19, while fiber intake decreased the odds of hospitalization due to COVID-19. The dynamical system models showed that dietary intake of cholesterol, PUFAs, and total sugar was associated with an increased risk of COVID-19, while fiber had a protective role.