Introduction

One-third of the global population, approximately 2.4 billion people, experienced moderate to severe food insecurity in 2022, making it a top priority for policymakers at all levels [1]. According to the Food and Agriculture Organisation of the United Nations, food insecurity is defined as a "lack of regular access to enough safe and nutritious food for normal growth and development and an active and healthy life" [2]. Food insecurity has been found to negatively impact mental health, increasing the risks of common mental health disorders such as stress, anxiety, depression, and sleep disorders [3,4]. Furthermore, severe mental illness, such as schizophrenia, bipolar affective disorder, and mood disorder with psychotic features, may, in turn, be a risk factor for food insecurity [5]. Finally, food insecurity may aggravate an existing severe mental illness [6].

The International Organization for Migration defines international migrants as “any person who is moving or has moved across an international border (…) away from his/her habitual place of residence” regardless of their migratory status [7]. In 2022, 281 million people were considered international migrants worldwide [8]. Recent research has documented food insecurity throughout the migratory cycle, as it is an important driver of migration worldwide and can also be experienced during transit and settlement in a new country [9,10,11,12]. It is important to note that international migrants are an extremely heterogeneous population group, and the experience of migrating varies widely, depending on reasons for migrating, country of origin, transit, arrival, race, gender, and social class, among other factors. In this context, not all international migrants have or will experience food insecurity, and the relationship between migration and poor mental health is not definitive [13]. However, from an intersectional viewpoint, gender, race, and class in the context of human mobility may lead to or exacerbate precarious circumstances that increase the risk of experiencing food insecurity, with an impact on mental health [14,15,16].

In this regard, some specific risk factors for food insecurity that have been found to impact mental health in the general population may be especially relevant to international migrants. These include discrimination [17], unemployment, informal or precarious employment as a result of irregular or temporary migratory status [18,19], having additional financial pressures related to sending remittances to support family in the country of origin [20,21], lack of access to nutrient-dense food like fruits and vegetables throughout the migratory cycle [22], experiencing relative food insecurity (in relation to the local population or their country of origin) [23], not being able to find or afford culturally relevant food [24], not being able to acquire food in a socially acceptable way [25], which may differ across different cultures [26], and having limited social support networks mediating the effect of food insecurity on mental health [27].

Furthermore, research suggests that food insecurity in migrant children is equal to that of migrant adults [28,29]. Considering that almost half (48.4%) of mental health disorders develop before the age of 18 years, with a peak median global onset of 14.5 years [30], food insecurity in this population may promote the onset of mental health conditions later in life, further compounding the mental health crisis [31]. Additionally, gender is relevant, considering that migration trends have become increasingly feminized, and food insecurity is strongly associated with poor mental health among women [27,32]. More specifically, transgender and gender non-conforming people experience higher unemployment, underemployment, and discrimination, leading to higher food insecurity [33] in this particular population [34]. Finally, these potential risk factors may have been exacerbated during the COVID-19 pandemic, as migratory flows declined due to border closures and other mobility restrictions that limited the opportunities to find work or access food banks[35,36].

The authors conducted a preliminary search in October 2023 in the scientific databases The Cochrane Database of Systematic Reviews, PubMed, Web of Science, as well as Google Scholar for existing scoping and systematic reviews on the topic. Several systematic, scoping, and narrative reviews have been conducted on migration, food insecurity, and health in general, without a specific focus on mental health [16,28,37,38,39,40,41,42]. Other systematic and scoping reviews have been conducted on migration and mental health without a specific focus on food insecurity [43,44,45,46,47]. Furthermore, a narrative review on food-related challenges and mental health among African migrants in the United States was recently published [48]. However, to the best of our knowledge, no scoping review has been conducted on food insecurity among international migrants in general, with a special focus on mental health.

In this context, this scoping review aims to gather and synthesize the available evidence on food insecurity and mental health among international migrants. The results of the review will be relevant to researchers in the field who are seeking to develop further studies on this topic, as well as policymakers in the field seeking to help address these issues.

Methods

Study design

A scoping review will be conducted according to the Joanna Briggs Institute guidelines [49]. The results will be reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review (PRISMA-ScR) [50]. This protocol is registered on the Open Science Framework platform and is accessible through the following link: https://osf.io/xt6a3

It was selected as a study design because the topic addressed in this article is at the intersection of three issues that have been researched separately, as shown in the introduction; however, it is necessary to explore the existing evidence encompassing all three dimensions. In that sense, conducting a scoping review is appropriate as it uses a systematic approach to review the available literature and maps the evidence from both scientific and grey literature; it includes a range of study designs, evaluates topics beyond intervention effectiveness, and identifies main concepts, theories, sources, and knowledge gaps [50,51,52].

Research question

The scoping review will address the two following research questions:

• What evidence is available on food insecurity and mental health among international migrants?

• How does the existing evidence link food insecurity and mental health among international migrants?

Eligibility criteria

Participants

This review will consider evidence that explicitly includes international migrants, as defined in the introduction, from any country with any migratory status and of all genders and ages. First and second-generation migrants will be considered. Second-generation immigrants are those born in a country where at least one first-generation immigrant parent resides and, in some cases, holds their nationality [53]. Evidence stating ethnicity without detailing the country of origin will be excluded. Evidence focusing only on internal migrants, defined as people moving within their country´s borders for any reason [54], will also be excluded.

Concept

The concept of interest in this scoping review is the interaction between food insecurity and mental health in the context of international migration. Any evidence focusing solely on the topic or reporting specific results as part of a broader focus will be included. We used the Food and Agriculture Organization's definition of food insecurity, presented in the introduction, and will encompass four dimensions: availability, access, utilization, and stability over time [55]. The World Health Organization (WHO) defines mental health as a complex continuum of mental well-being encompassing more than the absence of mental disorders [56]. In that sense, this scoping review will consider evidence describing symptoms and diagnosed conditions, including severe mental illness, as well as mental and emotional well-being, or its absence.

Context

Types of evidence sources

Any type of evidence, including other reviews and editorials. For feasibility reasons, only English, Spanish, French, Italian, or Portuguese studies published from 2013 to 2023 will be included in the review.

Search strategy

Evidence published in scientific journals will be identified through a search in the Web of Science, PubMed, Medline, APA PsycArticles, Cinahl, and ASSIA databases. As the review question is broad, an additional search on Google Scholar will be conducted to identify grey literature on the topic, including non-peer-reviewed reports. For feasibility reasons, only the first 100 search records on Google will be reviewed.

The research team developed the search strategy based on their expertise and previous experience conducting systematic and scoping reviews on related topics. It will include the following terms and will be adapted according to the technical specificities of each database:
International migrants
("transients and migrants" OR "emigrants and immigrants" OR "refugee" OR "asylum seeker" OR "migration background" OR "immigrant background" OR "migrant" OR "immigrant" OR "irregular migrant" OR "undocumented migrant" OR "nomad" OR "foreigner" OR "foreign-born" OR "foreign born" OR "displaced" OR "stateless" OR "state-less" OR "noncitizen" OR "non-citizen" OR "outsider" OR "newcomer" OR "newly arrived" OR "new arrival" OR "ethnic minority")

Expected results

The scoping review will map the existing evidence on the topic and how it links food insecurity and mental health among international migrants. To our knowledge, this is the first review to bring together international migration, food insecurity, and mental health. Food insecurity has been a global priority for several decades [57] and is a recognized social determinant of mental health. The circumstances and conditions under which international migration sometimes takes place create a context where food insecurity is experienced. As mental health is increasingly becoming an urgent concern for public health globally [58], it is of interest to explore its links with food insecurity in contexts where social vulnerability may be experienced. Furthermore, as the topic is expected to have been scarcely researched, the scoping review will contribute to:

• Identifying what is known about international migration, food insecurity, and mental health.

• Identifying gaps in the literature on the topic regarding research methods, studied population, and geographical areas.

• Identifying opportunities for specific research subtopics to be carried out in the future.

• Exploring how food insecurity and mental health may be linked in the existing literature.

This scoping review will have several strengths. The first is the application of a rigorous protocol following Joanna Briggs Institute and PRISMA-ScR guidelines. Registration and publication of the protocol will ensure transparency, enhancing the replicability and credibility of the review. The second has to do with the interdisciplinary expertise of the research team involved in the topics included in this review. This contributes to ensuring that the specificities of each of the three areas are properly addressed and represented, from the research terms to the conclusions that may be drawn. Finally, the decision to include grey literature allows for an inclusive approach to the topic outside of scientific evidence, which may ultimately provide a broader and enriched overview.

However, some limitations may be anticipated. The first one has to do with language limitations since evidence in languages other than those considered may exist. The second one is that although four scientific databases will be searched, as well as Google Scholar, some of the literature of interest may be involuntarily excluded.