Comments on “Impact of Socioeconomic Status on Dietary Intake in Adults Aged 60 and Over, in Northwestern Spain”

We read with great interest the article by Murillo-Zaldívar et al., which examined the association between socioeconomic status (SES) and dietary intake among community-dwelling older adults in Salamanca, Spain [1]. The finding that higher SES was associated with greater vegetable and cereal intake, while lower SES with higher saturated fat intake, reinforces the well-known socioeconomic gradient in diet quality. Particularly intriguing is the observation that participants with high SES consumed significantly more processed meats (e.g., cured meats, sausages) than those with middle SES. This counter-intuitive pattern deserves further methodological and conceptual consideration, which we wish to offer constructively. First, the measurement of SES deserves a closer look. The authors assigned SES based on the annual average income per person by residential street, using data from the Spanish National Statistics Institute, and then categorized participants into three income groups according to the 33rd and 66th percentiles. This ecological (area-based) approach is practical and commonly used, but it carries a risk of ecological fallacy—individuals living on the same street can have widely different personal incomes, yet they receive the same assigned SES value [2]. Although the authors adjusted for education level in sensitivity analyses (Table S2), education is a distinct dimension of SES and does not correct the potential misclassification of income at the individual level. In dietary studies, such non-differential misclassification may attenuate true associations or, in some cases, create spurious findings [3]. We therefore suggest that future studies in this field should incorporate individual-level income measures (e.g., self-reported annual household income) alongside subjective SES indicators such as perceived financial strain or the MacArthur Scale of Subjective Social Status, which often capture aspects of material resources that objective metrics miss [4]. Such subjective status measures have been validated and are particularly informative in older adult populations [5]. Second, the higher processed meat intake in the high-SES group is a novel and important finding. The authors hypothesize that this may reflect local cultural and social eating patterns in Salamanca/Castile and León, where cured meats (jamón, chorizo, etc.) are frequently consumed in tapas bars and dining-out settings that may be more accessible to higher-income individuals. While plausible, this hypothesis remains untested in the current study because no data were collected on eating-out frequency, food procurement channels (supermarket vs. specialty shops), or specific cultural attitudes toward processed meats. In fact, a growing body of evidence suggests that higher SES does not always translate to uniformly healthier choices; for example, in some Mediterranean contexts, higher income is associated with greater consumption of artisanal or premium processed meats, which are perceived as “traditional” or “gourmet” rather than unhealthy [6]. To move beyond speculation, we propose that future research combine quantitative FFQ data with qualitative methods (e.g., semi-structured interviews) or with validated questionnaires on food-related behaviors (e.g., frequency of eating out, motivations for food choice). Such an approach would help disentangle whether the observed association is driven by affordability, cultural capital, or simply greater opportunity for social eating. We fully acknowledge that the original study was cross-sectional and did not aim to establish causality. Our comments do not diminish the value of their work; rather, we believe that explicitly recognizing the ecological measurement issue and the need for culturally informed, multi-level data on processed meat consumption would strengthen future investigations. Understanding why higher SES older adults in Spain consume more processed meats is crucial for designing targeted nutritional interventions that go beyond simply improving access—they must also address culturally embedded eating practices. In summary, Murillo-Zaldívar et al. have provided valuable insights into socioeconomic disparities in dietary intake among older Spaniards. Complementing their findings with individual-level SES measures and deeper exploration of the cultural drivers of processed meat consumption would further advance the field. C.Q. and X.F. conceived the letter concept, performed the literature analysis, and drafted the manuscript. H.D. and Q.Y. critically revised the manuscript for important intellectual content and provided supervision. All authors approved the final version and agree to be accountable for all aspects of the work. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest. Data sharing is not applicable to this article as no new data were created or analyzed in this correspondence.