The nutrition transition – understanding the diets of Iranian adults

February 11, 2021

Diets in Iran

Similar to other parts of the world, chronic diseases are increasing in Iran. Based on WHO report in 2016, the prevalence of obesity and overweight among Iranian adults over 30 years of age was 24% and 60% respectively. It’s well known that diet is a key modifiable risk factor for obesity, yet little is known about the diets of Iranians, a Middle Eastern country undergoing a nutrition transition. Diet quality indices, which enable comparisons with dietary recommendations, have been developed for use around the world. However, no index has been developed for use in Iranians, thus researchers have been using existing indices. This raises the question of how appropriate these indices are for assessing the diet of Iranians. Thus, as part of my PhD, I investigated the applicability of two diet quality indices for use in Iran – the Healthy Eating Index and the Diet Quality Index-International – by examining their associations with sociodemographic and nutrient intakes and adequacy.

 What I did

I used data on 6,935 households from the cross-sectional and nationally representative National Comprehensive Study on Household Food Consumption Pattern and Nutritional Status (2001-2003). This is a large, nationally representative sample of households from all provinces of Iran. Information on household food and beverage intake was collected using three 24-hour dietary recalls and was used to calculate the aforementioned household diet quality indices. The collection of multiple days of dietary data is a strength of this method as it better reflects habitual intake. However, household dietary intake is less accurate than individual-level data. Due to high cost and complexity of collecting dietary data at the individual-level, low- and middle-income countries commonly use this method to provide information about population diets. The sociodemographic characteristics I examined were household age, education and rurality, while I assessed the intake and adequacy of a variety of nutrients.

What I found

My findings showed that higher household diet quality was associated with heads of household who were older, were higher educated and lived in urban areas. Higher household diet quality was associated with a higher intake of ‘positive’ nutrients, including fibre, iron, calcium, vitamin C and protein and lower intake of ‘risk’ nutrients, such as sodium. What’s more, higher household diet quality was associated with adequate intake of calcium, vitamin C and protein, while Diet Quality Index-International was also associated with adequate intake of iron.

Implications

This study demonstrates the applicability of two diet quality indices for assessing the diet quality of Iranian households. Also, results indicate that the Diet Quality Index-International may be more applicable for evaluating Iranian nutrient adequacy. These findings have implications for the assessment of diet quality in the Iranian population and may help policy makers to design culturally appropriate healthy eating recommendations.

What’s next

In the next steps of my research, I will assess associations between these diet quality indices and obesity risk. I will also use statistical dietary pattern techniques to examine the overall patterns of foods consumed by the Iranian population. Having experienced the nutrition transition in Iran first-hand, my hope is that findings from my research will inform Iranian dietary policies and interventions aiming to curb rising rates of obesity.

Sara Ebrahimi is a PhD student in the Institute for Physical Activity and Nutrition, Deakin University. Her PhD thesis aims to understand the dietary patterns of Iranian households. This blog is about her recent publication in Nutrition Journal.