Do Migrants Eat Better Than Everyone Else? A sweeping review says the answer is complicated

When people move across borders, almost everything about their lives changes: their work, their neighborhood, their language, and, less visibly but just as profoundly, the food on their plates. Nutrition scientists have long debated whether that dietary upheaval leaves immigrants eating better or worse than the people around them. A new systematic review published in BMC Public Health by Ali Kohanmoo of Shiraz University of Medical Sciences and sociologist Asghar Mirfardi of Shiraz University offers the most organized answer to date, and its central finding is a striking paradox: on balance, immigrants tend to eat better than the native-born populations of the countries they move to, yet some migrant groups end up with markedly worse diets than anyone else in the picture.

The review, published open access on 3 October 2026, set out to bring order to a literature that has produced stubbornly inconsistent results. Rather than running a new experiment, the authors conducted a comprehensive search of three major bibliographic databases, PubMed, Scopus, and Web of Science, hunting for quantitative studies published between 2000 and November 2024 that measured diet quality in adult immigrants and compared it against a meaningful reference group. That comparison could take one of three forms: immigrants versus the native-born population of the destination country, immigrants versus the native-born population of their country of origin, or the same individuals measured before and after migration. Only studies meeting these criteria, framed by the authors in a Population, Exposure, Comparator, Outcome, Study design, or PECOS, structure, were eligible.

Nineteen studies survived the screening process. That number may sound modest for a field as globally significant as migration and health, but it reflects how demanding the inclusion criteria were: the studies had to use validated quantitative indices of diet quality rather than loose proxies such as single food items or self-reported general eating habits, and they had to include an explicit non-migrant comparison group. Fifteen of the nineteen studies compared immigrants with the native-born population of their destination country. Within that group, seven studies found immigrants had higher diet quality, two found lower diet quality, and the remaining six reported mixed results, with outcomes differing either between immigrant groups or between the different diet quality indices used to score the same diets.

The second comparison strategy yielded a similarly nuanced picture. Five studies compared immigrants with the native-born residents of their countries of origin, effectively asking whether moving to a wealthier country improved the quality of what people ate relative to those who stayed behind. Three of those studies found immigrants eating better, one found them eating worse, and one found no significant difference at all. Finally, a single study took the most direct approach of all, tracking diets before and after immigration, and observed a decline in diet quality following the move. That lone longitudinal data point is a reminder that the aggregate statistics can conceal real individual trajectories of dietary deterioration.

Why would immigrants so often out-eat their new neighbors? The authors point to a cluster of mechanisms that researchers have been refining for decades. Many migrants arrive from food cultures built around home-cooked meals, fresh produce, legumes, and traditional dietary patterns that happen to align well with modern healthy eating indices such as the Alternative Healthy Eating Index, the Alternate Mediterranean Diet score, or the Healthy Eating Index. Compared with the highly processed, convenience-driven diets common in high-income destination countries, those inherited patterns can look remarkably protective. The review’s finding that most immigrant groups showed higher diet quality than non-migrants is consistent with this interpretation: the baseline diet a person brings with them can be better than the one waiting for them at the destination.

But the same review shows how quickly that advantage can erode, and for whom. The studies that reported poorer diet quality among immigrants concentrated in socioeconomically underprivileged groups, where the forces that shape eating are less about cultural heritage and more about budget, time, and access. The authors identify length of residence in the destination country as a key variable, reflecting the well-documented process of dietary acculturation: as migrants spend more years in a new food environment, their diets tend to converge toward local norms, and not always in a healthy direction. Educational attainment, financial status, and occupational conditions also emerged as contributing factors, as did food culture itself, the shared expectations and practices that determine what a family considers a proper meal.

Methodology matters too, and the review is unusually candid about this source of heterogeneity. Diet quality is not a single measurable quantity like blood pressure; it is a constructed score, and different indices weight different things. The studies included in the review used a wide array of instruments, among them the Healthy Eating Index, the Alternative Healthy Eating Index, the Alternate Mediterranean Diet score, the Diet Quality Index and its international variant DQI-I, the Dietary Diversity Score, the Food Variety Score, the Dietary Guidelines Index-2013, the Healthful Plant-based Diet Index, and the Pyramid-based Mediterranean Diet Score. A diet that scores well on a Mediterranean-style index might score only modestly on a diversity-based measure, and vice versa. Six of the fifteen destination-country comparisons reported mixed results precisely because different indices or different migrant subgroups produced different verdicts within the same study.

The practical implications reach well beyond academic taxonomy. Public health agencies in immigrant-receiving countries often design nutrition interventions on the assumption that migrants are a uniformly vulnerable population, and this review complicates that assumption in a useful way. If most immigrant groups eat better than their non-migrant neighbors, blanket dietary warnings aimed at migrant communities may miss the mark. The groups that genuinely need support are identifiable and specific: those facing economic precarity, those who have lived in the destination country long enough for dietary acculturation to take hold, and those whose food culture has been disrupted without being replaced by an equally healthy alternative. Targeted interventions grounded in socioeconomic status and length of residence, the review suggests, would be far more efficient than one-size-fits-all messaging.

There is also a broader scientific lesson in the paper’s structure. By explicitly separating the three comparison frames, destination-country natives, origin-country natives, and pre-migration baselines, the authors show that the question “do immigrants eat better or worse?” is not one question but three, and answers to one frame do not transfer to the others. An immigrant may eat better than a stay-at-home compatriot while eating worse than their new next-door neighbor, and both facts can be true simultaneously because the reference points measure different things: the effect of leaving versus the effect of arriving. The single before-and-after study, showing a decline in diet quality after migration, hints that the transition itself, with its stress, changed schedules, and unfamiliar food markets, may push diets downward even when the destination country offers greater abundance.

The review’s conclusion distills all of this into a single framing that is likely to shape future research: diet quality among immigrants is a function of multiple social, cultural, and economic factors, with socioeconomic status standing out as especially decisive. That is a more sophisticated picture than the simple narrative of migration as either dietary rescue or dietary ruin, and it sets a clear agenda. Future studies, the authors imply, should stop asking whether migrants eat well and start asking which migrants, under which conditions, measured with which instruments, and at what point in their migration journey. With international migration continuing to reshape the demographics of nearly every high-income country, the answer to that refined question will help determine whether the food systems of destination countries become a source of health for newcomers or another axis along which inequality is written into the body.

Subject of Research: Comparative diet quality of adult immigrants versus non-migrant populations

Article Title: Diet quality of adult immigrants compared with non-migrants: a systematic review of quantitative studies

Article References: Kohanmoo, A., & Mirfardi, A. (2026). Diet quality of adult immigrants compared with non-migrants: a systematic review of quantitative studies. BMC Public Health. https://doi.org/10.1186/s12889-026-29748-1

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29748-1

Keywords: diet quality, immigrants, migration, systematic review, public health, nutrition, dietary acculturation, socioeconomic status, Healthy Eating Index, Mediterranean diet, food culture, BMC Public Health