This cross-sectional study described food insecurity and its associated factors among Shiraz suburban households in southwest Iran. The findings suggest that the food insecurity prevalence was 87.2% (53.87% were moderately and 33.3% were severely hungry). According to the obtained findings, the portion of more than half of one’s income to food purchases increases the chances for food insecurity. Statistically, self-employment, employment by others, retirement, moderate socioeconomic status, and spending more than 30 million Rials (Iran’s currency equal to 110 US$) per month on family expenses were protective factors against food insecurity.

Our findings highlighted that food insecurity is more prevalent among the slum area residents in the southwest of Iran. Based on previous studies, the prevalence of food insecurity in different regions of Iran ranges from 27.8% (urban residents of Shiraz) to 82% (slums of Kerman) [14, 28], which is due to a recent increase in the dust because of wetlands drying up in the southwest and the shortage of water, agricultural mismanagement and low quality of living standards in the southeast of Iran that has led people to migrate to better-off places with job opportunities, such as Shiraz, and staying in suburban areas [29].

A meta-analysis conducted in Iran in 2004 revealed that the prevalence of mild, moderate, and severe food insecurity is 9.3%, 5.6%, and 3.7%, respectively. However, a similar study conducted in 2015 revealed a 49% prevalence [7, 30]. It shows that the trend of food insecurity has increased recently in Iran. Meanwhile, food security has improved significantly in other developing countries, such as India [31]. Evidently, the prevalence of food insecurity was higher in rural and slum than the urban areas [14, 32,33,34].

Furthermore, studies imply that the prevalence of food insecurity in developing countries is remarkably higher in developed countries. For instance, the prevalence of food insecurity in Lebanon, Nigeria, Nairobi, and Kampala was 50%, 81%, 87%, and 93%, respectively, while it was 16.5% and 15.9% in Portugal and Canada, respectively [35,36,37,38,39,40]. This indicates that food insecurity is a concerning issue in developing countries. Noticeably, the tools used in various studies for measuring food insecurity were different; thus, comparing different studies should be done cautiously.

Omidvar et al. clustered MENA countries based on GDP and political stability, showing that the frequency of severe food insecurity was significantly different amongst the clusters. Severe food insecurity was 5%, 13.6%, and 26.7% in rich, stable countries, middle-low income with less political stability, and middle-low income politically unstable countries [18].

The socioeconomic status of the households was the most substantial factor associated with food insecurity in the current study; this finding is consistent with those of previous papers in both developed and developing countries [31, 37, 39, 41,42,43]. The World Bank reported Iran’s poverty rate for 2019 at 17.80%, showing a 3.8% increase from 2018 [44]. Notably, 81.2% of the studied families were categorized as having low socioeconomic status, and 44.4% spent more than half of their monthly income on food. Food insecurity has been discovered to be a significant issue among low-income households. In slum areas, unlike rural ones, most households were immigrants, and due to insufficient natural resources and land for agriculture, their heads worked as manual workers with low wages. [45]. On the other hand, in this study, some active people were jobless, which could worsen the economic status of their households. The overall unemployment rate for 2021 was 11.46% in Iran, based on World Bank reports [46]. In the slum areas of Ahvaz, southern Iran, 16% of households’ heads were unemployed or job-seekers [45]. Furthermore, the present study showed that female-headed households are more likely to have severe food insecurity than male-headed households, consistent with studies conducted in the United States and Kenya [47, 48]. This gender difference revealed that female-headed households would be the top priority for promoting food security programs. As other countries’ experiences show, governmental equity-oriented interventions are required to combat the socioeconomic roots of food insecurity [47,48,49].

According to our results, the proportion of the members with chronic diseases in the food-insecure group was significantly higher than that of the secure group, consistent with previous studies [35, 50]. In India, households with a physically disabled family member were twice prone to food insecurity [35]. Dean et al. showed that chronic diseases are strenuously linked to food insecurity and higher healthcare expenditures [51]. Evidently, each 1.0 percentage point enhancement in insurance coverage was associated with a food insecurity reduction of 0.4 percentage points [52]. Assisting people in getting health insurance could start a virtuous cycle of improving consequences for health and healthcare as well as food insecurity [52]. A role for such developments in comprehensive anti-poverty strategies may be recommended by food security improvement following the development of health insurance [53].

Similar to studies from Canada and urban areas of Iran, food insecurity was more prevalent in households headed by females than males [33, 43, 50]. Although these households require additional assistance, our findings showed that more than 90% did not receive enough assistance from charities, which was significantly associated with food insecurity in these people. Charities, non-governmental organizations (NGOs), and governmental organizations could have notable roles in empowering female-headed households. Targeted programs for increasing their knowledge and skills, supporting the production and sale of household products (such as sewing, cooking, baking, handicrafts, and jewelry making), and other income-generating skills, such as child and elderly care, can be suggested for planning and implementation regarding cultural, social, and environmental potentials, via these NGOs [54, 55]. Female-headed families in Iran were the subject of a qualitative investigation revealing numerous difficulties that could pose a serious threat [18]. To reduce household food insecurity, governmental organizations should prioritize training them to adapt their new and multidimensional functions, supplying more financial assistance, and supporting them in raising their social standing.

Previous studies in Iran showed that the sanctions and poor domestic policies had significant negative impacts on Iran’s economy. However, among all households, some vulnerable groups suffered more, and sanctions drastically decreased their welfare [18].

Notably, the coincidence of Iran’s economic sanctions and the COVID-19 epidemic has reduced Iranians’ food-purchasing power, exacerbating food insecurity among the middle and low-socioeconomic populations [15]. On the other hand, it has caused an economic recession in Iran, reducing the government’s ability to support low-income families [15, 56]. According to the obtained results, there was no statistically significant relationship between COVID-19 and unemployment or decreased income; meanwhile, it did have a close to significant association (P = 0.058) with the decrease in food-purchasing power. Although mismanagement of agricultural sectors in the supply and distribution of food at reasonable prices despite climate change and lack of water resources could not be ignored, Economic sanctions starting over one year before the onset of the COVID-19 epidemic were effective in disturbing the Iranian’s economic status and reducing their purchasing power. In other MENA region countries such as Lebanon, results showed that after the COVID-19 pandemic, food insecurity was estimated at 36% to 39%, with a 50–70% reduction in the population’s income [57]. Moreover, after the COVID-19 pandemic, half the studied population had a low food consumption score, more than half of the households ate less than two meals per day, and about 70% of them missed their meals to spare food [58].

The most important strengths of the present study are as follows: first of all, the results were representative of the general population due to the sampling method. Second, sample size of the study was considered appropriate to guarantee the study’s power. Third, data collection was done with validated tools and a face-to-face method. Finally, an adjusted odds ratio was calculated to determine the association between food insecurity and its contributing factors, resulting in most confounding effects being adjusted.

One of the most significant limitations of this study was its cross-sectional design, limiting the researchers’ ability to investigate the causal pathways between food insecurity and various risk factors. Furthermore, information on the recent trend of food insecurity could not be provided due to the nature of the study. There was a possibility of selection bias by the people not participating in the study due to personal issues and shame. Furthermore, information was possible bias due to their consideration of drawing attention to themselves or shame about their situation.