Abstract
Objectives
This study examined the association between household food security and social isolation among US adults and differences by age. To evaluate their joint impact on health, we examined whether both experiences are independently associated with less healthy functioning across intrinsic capacity (IC) domains, and whether social isolation modifies the food security-IC relationships.
Methods
Data were from 14,570 non-institutionalized adults ≥20 years from the 2007 to 2018 National Health and Nutrition Examination Surveys. Food security was measured using the US Household Food Security Survey Module. Social isolation was measured with a composite score capturing marital status, household size, and social participation. IC encompassed five domains: cognition, vitality, locomotion, sensory function, and psychological well-being. Multivariable logistic regressions examined these associations, adjusting for sociodemographic and health covariates.
Results
Compared to high food security, marginal food security (OR 1.29, 95% CI 1.05–1.60), low food security (OR 1.36, 95% CI 1.08–1.71), and very low food security (OR 1.95, 95% CI 1.61–2.37) were associated with greater social isolation after multivariable adjustment. This association was more robust among adults ≥40 years. Among adults ≥40 years, food insecurity and social isolation independently predicted with less healthy functioning across all IC domains. Across most domains, social isolation did not significantly modify the food security-IC associations.
Conclusions
There was a graded association between food insecurity and social isolation after accounting for social disadvantage. Both experiences independently predicted lower IC. These findings underscore the need for public health interventions to address food insecurity and social isolation to better promote healthy aging.
Keywords: Food insecurity, Social isolation, Intrinsic capacity, NHANES, Age differences
1. Introduction
Food insecurity, or insufficient access to adequate food, is a fundamental social determinant of health affecting 13.7% of US households in 2024 [1]. Food insecurity contributes to poor diet quality and diet-sensitive disease [2]. However, a growing number of studies have also shown that food insecurity can act as a chronic stressor and is associated with multiple dimensions of poor mental health, including psychological distress, anxiety, and depression [[3], [4], [5], [6]]. Food insecurity could plausibly affect health outcomes through both biobehavioral and psychosocial pathways [7].
In parallel, social isolation, characterized by a lack of social connections or support, is a growing epidemic with important health implications [8]. Social isolation has been associated with increased risks of poor mental health, as well as adverse physical health outcomes including cardiovascular disease, dementia, and all-cause mortality [[9], [10], [11]]. While separate strands of research have shown food insecurity and social isolation are key contributors to poor mental health across the life course [2,3,7,12], limited work has considered how they may affect each other or downstream health outcomes when they co-occur. Food insecurity and social isolation both share structural determinants and disproportionately affect individuals with lower socioeconomic status. Food insecurity could lead to greater social isolation due to social stigma, and social isolation could lead to greater food insecurity due to a lack of social networks for food support [13,14]. Understanding the relationship between food insecurity and social isolation has important implications for future research seeking to understand social determinants of health.
To date, only a few studies have examined this relationship. In one study using data from the Medical Expenditure Panel Survey, more food insecurity was associated with greater social isolation and loneliness after adjusting for sociodemographic characteristics [15]. In this study, food insecurity was binarized, limiting the ability to look at the association with social isolation across food security categories. Another study found that social isolation exacerbated the association between food insecurity and mental illness; however, the association between food insecurity and social isolation was not directly examined [16]. More research is needed to understand the association between food insecurity and social isolation, and whether there are differences by age given that older adults typically report less food insecurity but greater social isolation compared to younger adults [1].
Given prior work demonstrating associations between food insecurity or social isolation with poorer mental health, it is plausible that the co-occurrence of these experiences would also influence other aspects of health, though less research has directly examined this question. In 2015, the World Health Organization introduced the concept of intrinsic capacity (IC) as the “composite of all of the physical and mental capacities that a person can draw on at any point in time.” IC encompasses multiple domains for which higher functioning is important for healthy aging, including cognition, vitality, locomotion, sensory function, and psychological well-being [17]. While some research has shown that food insecurity or social isolation, considered separately, are associated with poorer functioning in some domains such as cognition [18,19] or psychological well-being [10,20], no study has examined food insecurity and social isolation as joint predictors of IC across all domains. Given the growing prevalence of food insecurity and social isolation in the US aging population, this research can provide an understanding of how structural drivers may shape healthy aging, which could then be used to inform public health interventions.
The primary objective of this study was to examine the association between household food security and social isolation and the modifying role of age in a nationally representative sample of adults. The secondary objective was to examine whether household food security and social isolation are independently associated with healthy functioning across multiple domains of IC, and whether social isolation modifies the associations between household food security and IC domains. We hypothesized food insecurity would be associated with social isolation in a stepwise manner after adjusting for sociodemographic confounders and that this association would be observed across all age groups. We also hypothesized that food insecurity and social isolation would both be associated with less healthy functioning in IC domains, and that the associations between food insecurity and IC domains would be stronger among adults with social isolation.
2. Material and methods
Data came from the 2007 to 2018 National Health and Nutrition Examination Surveys (NHANES). NHANES is an ongoing, multistage cross-sectional survey representative of the civilian, noninstitutionalized US population. In the present study, data from the in-home interview were drawn from 14,570 adults ages 20 years and older with non-missing data on household food security, social isolation, and study covariates. The National Center for Health Statistics Ethics Review Board reviews and approves all NHANES study protocols. Additional IRB review was waived because this study used publicly available, de-identified secondary data.
Household food security was measured via the validated US Household Food Security Survey Module [21]. Eighteen questions query whether experiences or behaviors of reduced food quality or intake are attributed to insufficient resources to purchase food over the last 12 months. Affirmative responses are summed to create a score; higher scores indicate more severe food insecurity. Food security levels were categorized as high, marginal, low, and very low according to USDA guidelines [21].
Social isolation was measured using a composite score (0–4) previously developed for the NHANES and comprising four separate questions on marital status, household size, and self-reported difficulty with activities related to social participation [22]. One point is assigned to adults who are unmarried, widowed, divorced, or separated. One point is assigned to individuals living alone. One point is assigned for difficulty with the item: “going out shopping, watching movies or participating in sports activities.” One point is assigned for difficulty with: “participating in social activities (visiting friends, attending clubs or meetings, attending parties).” Items are summed and a score of ≥3 was used to indicate social isolation [22].
IC is a multidimensional concept comprising cognition, vitality, locomotion, sensory function, and psychological well-being. As there currently is no widely adopted tool to measure IC, for this exploratory analysis we used proxy indicators to define healthy function across each domain following methodology from prior NHANES studies [23,24]. Cognition was assessed with one item on “trouble concentrating on things” from the Patient Health Questionnaire (PHQ-9) [25], queried on a scale of 0 (not at all) to 3 (nearly every day). Cognitive function was considered healthy when participants reported “not at all” versus any other frequency. Vitality was assessed with two items derived from different questionnaires: one question from the Weight History questionnaire queried unintentional weight loss ≥10 pounds over the past year (yes/no) [26], and one question on experiencing “poor appetite or overeating” queried on a scale of 0 (not at all) to 3 (nearly every day) from the PHQ-9 [25]. Vitality function was considered healthy according to whether individuals reported no unintentional weight loss and “not at all” for changes in eating behavior. Locomotion function was assessed with one question about perceived difficulty “standing up from an armless straight chair” (yes/no) from the physical functioning questionnaire [27]. Locomotion function was considered healthy when participants reported no difficulty. Sensory function included seeing and hearing ability, but due to data limitations, sensory domains were examined separately. Seeing ability was assessed with one question (yes/no) on “trouble seeing, even when wearing glasses or contact lenses” from the 2007–2010 medical conditions questionnaire [28], which was later modified to “serious difficulty seeing even when wearing glasses” from the 2011–2018 disability questionnaire [29]. Seeing ability was scored as healthy if participants reported no trouble or difficulties. Hearing ability was assessed with one question on self-reported general hearing condition from the audiometry questionnaire [30]. Hearing function was defined as healthy if participants reported “excellent” or “good” hearing, and unhealthy if participants reported “a little trouble,” “moderate hearing trouble,” “a lot of trouble,” or “deaf”. NHANES did not collect audiometry data in the 2013–2014 cycle; thus, NHANES participants in this cycle were excluded from the hearing-related sensory function analysis. Psychological well-being was assessed using two questions from the PHQ-9 [25]– “feeling down, depressed, or hopeless” and “having little interest or pleasure in doing things,” each queried on a scale of 0 (not at all) to 3 (nearly every day). Psychological function was characterized as healthy when participants reported “not at all” to both questions. All IC outcomes were categorized as less healthy functioning (1) versus healthy functioning (0).
Sociodemographic and health covariates were measured via self-report in the in-home interview and included age, sex, race and ethnicity, educational attainment, income-to-poverty ratio, and prior diagnosis of major chronic disease (diabetes, congestive heart failure, coronary heart disease, angina, heart attack, or stroke). We examined level of household food security by sociodemographic characteristics. We used multivariable logistic regression models to examine the associations between household food security and social isolation adjusting for all sociodemographic and health covariates. Tests for trend were conducted by including household food security as an ordinal variable. We then tested for heterogeneity in the main association by age. Where a significant interaction was found, we present stratified associations by age category. Finally, we used multivariable logistic regression models to examine less healthy functioning in individual IC domains with household food security and social isolation as exposures in middle-aged and older adults, adjusting for all covariates. We also examined whether social isolation modified the associations between household food security and IC domains using interaction terms. Complex interview and MEC weights were recalculated using NHANES guidelines [31] and used in all analyses to account for different sampling probabilities across the 12-year period.
3. Results
In our analytic sample, 74.3% of adults had high food security, 8.8% had marginal food security, 9.0% had low food security, and 8.0% had very low food security. Table 1 shows sociodemographic and health characteristics stratified by household food security. Compared to adults with high food security, those with marginal, low or very low food security were more likely to be younger, identify as minority race or ethnicity, have lower educational attainment, have lower family incomes, and have a previous diagnosis of chronic disease. In addition, adults with marginal, low or very low food security versus high food security had a higher prevalence of each of the four social isolation indicators and less healthy functioning on cognition, vitality, locomotion, sensory function (seeing), and psychological well-being.
Table 1.
Characteristics of the analytic sample stratified by household food security status among US adults ≥20 years (NHANES 2007–2018).
| Overall (n = 14,570) |
High food security (n = 9817) |
Marginal food security (n = 1618) |
Low food security (n = 1780) |
Very low food security (n = 1355) |
P | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n | %a | n | %a | n | %a | n | %a | n | %a | ||
| Age | <0.0001 | ||||||||||
| 20−39 years | 1393 | 12.4 | 608 | 8.3 | 224 | 20.7 | 288 | 23.0 | 273 | 28.8 | |
| 40−59 years | 2692 | 22.4 | 1231 | 16.9 | 419 | 34.3 | 537 | 38.1 | 505 | 42.1 | |
| ≥60 years | 10,485 | 65.3 | 7978 | 74.7 | 975 | 45.0 | 955 | 38.8 | 577 | 29.1 | |
| Sex | 0.0003 | ||||||||||
| Male | 7135 | 46.3 | 4939 | 47.2 | 756 | 44.6 | 790 | 40.6 | 650 | 45.2 | |
| Female | 7435 | 53.7 | 4878 | 52.7 | 862 | 55.4 | 990 | 59.4 | 705 | 54.8 | |
| Race and ethnicity | <0.0001 | ||||||||||
| NH White | 7033 | 74.2 | 5325 | 80.1 | 543 | 56.7 | 584 | 53.0 | 581 | 62.4 | |
| NH Black | 3159 | 10.2 | 1947 | 7.9 | 446 | 17.6 | 439 | 17.1 | 327 | 15.2 | |
| Hispanic | 3061 | 9.2 | 1635 | 6.0 | 474 | 17.5 | 587 | 20.9 | 365 | 16.1 | |
| NH Other or Multi-racial | 1317 | 6.4 | 910 | 5.9 | 155 | 8.2 | 170 | 9.0 | 82 | 6.3 | |
| Education | <0.0001 | ||||||||||
| <12 years | 4337 | 19.1 | 2347 | 14.6 | 623 | 27.6 | 816 | 37.2 | 551 | 31.1 | |
| High school graduate or equivalent | 3560 | 25.8 | 2364 | 24.6 | 419 | 30.6 | 437 | 28.5 | 340 | 28.5 | |
| Some college | 4002 | 30.5 | 2759 | 30.6 | 429 | 30.7 | 429 | 28.5 | 385 | 32.3 | |
| College graduate or higher | 2671 | 24.6 | 2347 | 30.2 | 147 | 11.1 | 98 | 5.8 | 79 | 8.1 | |
| Poverty level | <0.0001 | ||||||||||
| <100% FPL | 3608 | 30.1 | 1392 | 19.1 | 595 | 36.8 | 855 | 47.0 | 766 | 55.1 | |
| 100−130% FPL | 1767 | 15.3 | 969 | 14.5 | 247 | 14.2 | 315 | 16.7 | 236 | 18.6 | |
| 130−200% FPL | 2603 | 26.9 | 1672 | 29.0 | 393 | 31.1 | 343 | 23.8 | 195 | 16.3 | |
| 200−300% FPL | 1274 | 15.7 | 954 | 20.4 | 136 | 11.2 | 114 | 8.2 | 70 | 6.9 | |
| >300% FPL | 948 | 12.0 | 769 | 17.0 | 82 | 6.7 | 64 | 4.2 | 33 | 3.1 | |
| Diagnosis of major chronic diseaseb | 5275 | 30.6 | 3437 | 29.7 | 626 | 32.9 | 712 | 35.3 | 500 | 31.4 | 0.01 |
| Social isolation indicators | |||||||||||
| Never married, separated, divorced, or widowed | 6580 | 40 | 4047 | 35.5 | 819 | 50.2 | 915 | 52.3 | 799 | 56.8 | <0.0001 |
| Lives alone | 3276 | 20.3 | 2271 | 20.4 | 321 | 19.5 | 304 | 16.5 | 380 | 25.4 | 0.004 |
| Difficulty with shopping, movies, sporting events | 4160 | 25.8 | 2159 | 19.9 | 594 | 36.9 | 757 | 42.8 | 650 | 48.9 | <0.0001 |
| Difficulty with social activities | 3716 | 23.1 | 1832 | 16.7 | 532 | 34 | 728 | 42.2 | 624 | 48.8 | <0.0001 |
| Intrinsic capacity domains (less healthy functioning) | |||||||||||
| Cognition | 2172 | 18.9 | 1119 | 14.5 | 290 | 27.5 | 384 | 33.9 | 379 | 42.8 | <0.0001 |
| Vitality | 3833 | 31.3 | 2189 | 25.9 | 481 | 43.8 | 605 | 49.5 | 558 | 58.2 | <0.0001 |
| Locomotion | 3808 | 25.9 | 2168 | 21.6 | 519 | 36.1 | 627 | 42.7 | 494 | 44.6 | <0.0001 |
| Sensory function (seeing) | 2577 | 16.4 | 1414 | 13.0 | 348 | 23.2 | 435 | 28.1 | 380 | 33.6 | <0.0001 |
| Sensory function (hearing)c | 1595 | 17.6 | 1096 | 17.6 | 169 | 17.3 | 185 | 16.8 | 145 | 18.3 | 0.95 |
| Psychological well-being | 4407 | 36.6 | 2486 | 30.3 | 575 | 51.4 | 709 | 59.1 | 637 | 67.5 | <0.0001 |
FPL, federal poverty level; NH, non-Hispanic.
Percentages incorporate complex survey weights that account for sampling probabilities and participation rates across the analytic period.
Indicates prior diagnosis of diabetes, congestive heart failure, coronary heart disease, angina, heart attack, or stroke.
Audiometry data was not available for NHANES 2013–2014.
The prevalence of social isolation was 12.2%. After adjustment for sociodemographic and health characteristics, relative to high food security, marginal food security (OR 1.27, 95% CI 1.03, 1.58), low food security (OR 1.29, 95% CI 1.03, 1.62), and very low food security (OR 1.89, 95% CI 1.56, 2.28) were each associated with higher likelihood of social isolation in a stepwise manner (P-trend < 0.0001; see Table 2). Significant differences emerged by age (P-interaction = 0.006). Significant associations between greater severity of food insecurity and social isolation were strongly evident for adults 40−59 years (P-trend < 0.0001) and adults ≥60 years (P-trend < 0.0001); there were no significant associations for adults 20−39 years.
Table 2.
Multivariable-adjusted associations between household food security status and social isolation among US adults ≥20 yearsa (NHANES 2007–2018).
| Overall |
20−39 year olds |
40−59 year olds |
≥60 year olds |
|||||
|---|---|---|---|---|---|---|---|---|
| ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | |
| High food security | Ref. | Ref. | Ref. | Ref. | ||||
| Marginal food security | 1.27 | 1.03, 1.58 | 0.54 | 0.25, 1.16 | 1.59 | 1.07, 2.36 | 1.25 | 0.97, 1.60 |
| Low food security | 1.29 | 1.03, 1.62 | 0.88 | 0.56, 1.40 | 1.34 | 0.96, 1.86 | 1.44 | 1.06, 1.94 |
| Very low food security | 1.89 | 1.56, 2.28 | 1.00 | 0.62, 1.60 | 2.03 | 1.49, 2.77 | 2.35 | 1.73, 3.17 |
| P-trend | <0.0001 | 0.91 | <0.0001 | <0.0001 | ||||
Household food security was measured using the 18-item US Household Food Security Survey Module and categorized according to USDA guidelines. Social isolation was measured using a four-item composite score including marital status, household size, and reported difficulty participating in social activities.
Models adjusted for age (excluding age-stratified models), sex, race and ethnicity, education, income to poverty ratio, diagnosis of major chronic disease, and survey year.
Given the fact that significant differences were observed for adults ages 40 and older, and that the concept of IC was developed to promote healthy aging, associations with IC domains focused on adults ≥40 years. Relative to high food security, marginal food security, low food security, and very low food security were consistently associated with less healthy functioning across the cognition, vitality, locomotion, sensory function (seeing), and psychological domains in a stepwise manner (P-trend < 0.0001); no significant associations were observed with the sensory function (hearing) domain (Table 3). Social isolation was associated with less healthy functioning on cognition (OR 2.10, 95% CI 1.76, 2.49), vitality (OR 1.93, 95% CI 1.65, 2.25), locomotion (OR 5.47, 95% CI 4.71, 6.34), sensory function (seeing) (OR 1.91, 95% CI 1.60, 2.27), sensory function (hearing) (OR 1.86, 95% CI 1.54, 2.25), and psychological well-being (OR 2.20, 95% CI 1.88, 2.57). Social isolation did not significantly modify the associations between household food security and IC domains (P-int > 0.05), with the exception of locomotion (P-interaction = 0.003) and sensory function (hearing) (P-interaction = 0.03). For locomotion, the associations with household food security categories were stronger for adults not socially isolated; for sensory function (hearing), adults who were socially isolated had lower odds of less healthy function (Supplemental Table 1).
Table 3.
Multivariable-adjusted associations between household food security status, social isolation and less healthy functioning in intrinsic capacity domains (cognition, vitality, locomotion, sensory function, and psychological well-being) among US adults ≥40 years (NHANES 2007–2018).
| Cognition |
Vitality |
Locomotion |
Sensory function (seeing) |
Sensory function (hearing)a |
Psychological well-being |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | |
| Household food security | ||||||||||||
| High food security | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. | ||||||
| Marginal food security | 1.42 | 1.12, 1.81 | 1.35 | 1.09, 1.67 | 1.43 | 1.21, 1.70 | 1.42 | 1.14, 1.77 | 1.05 | 0.84, 1.32 | 1.71 | 1.43, 2.04 |
| Low food security | 1.70 | 1.39, 2.09 | 1.58 | 1.31, 1.91 | 1.67 | 1.38, 2.01 | 1.77 | 1.40, 2.24 | 0.93 | 0.70, 1.24 | 1.89 | 1.54, 2.32 |
| Very low food security | 2.17 | 1.71, 2.77 | 1.86 | 1.55, 2.22 | 1.39 | 1.07, 1.82 | 2.19 | 1.73, 2.79 | 1.01 | 0.72, 2.25 | 2.49 | 1.94, 3.19 |
| P-trend | <0.0001 | <0.0001 | <0.0001 | <0.0001 | 0.87 | <0.0001 | ||||||
| Social isolation | ||||||||||||
| Not isolated | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. | ||||||
| Isolated | 2.10 | 1.76, 2.49 | 1.93 | 1.65, 2.25 | 5.47 | 4.71, 6.34 | 1.91 | 1.60, 2.27 | 1.86 | 1.54, 2.25 | 2.20 | 1.88, 2.57 |
Audiometry data was not available for NHANES.2013–2014
Models adjusted for age, sex, race and ethnicity, education, income to poverty ratio, diagnosis of major chronic disease, and survey year. Models included household food security categories and social isolation together.
4. Discussion
The primary study objective was to examine the association between food insecurity and social isolation in a large, nationally representative study. Our results showed a clear stepwise pattern across the food security spectrum and social isolation after accounting for social disadvantage; even marginal food security was significantly associated with isolation, while very low food security nearly doubled the odds. These findings expand upon a sparse body of literature characterizing the association between food insecurity and social isolation [[14], [15], [16],32]. The association between food insecurity and social isolation was prominent among middle-aged adults and older adults but was attenuated among younger adults (<40 years). Several mechanisms could explain these results. Because younger adults are often navigating transitions in education, employment, and financial independence, there may be a greater capacity to leverage their social networks for food assistance [33]. Conversely, expectations of financial stability increase with age; middle-aged and older adults may have heightened feelings of shame associated with food insecurity, isolating themselves to hide their condition [20]. For older adults, food insecurity is correlated with mobility limitations, transportation barriers, and chronic health conditions, all of which could impede regular and frequent social interactions [34].
Food insecurity and social isolation likely co-exist and may have additive effects on health. Our secondary analysis extending to IC showed that food insecurity and social isolation were each strongly associated with less healthy functioning across multiple domains of IC (cognition, vitality, locomotion, sensory function (seeing), and psychological well-being) even after adjusting for sociodemographic and health characteristics and when modeled together, suggesting that these social determinants may influence healthy aging through independent pathways. The magnitude of some associations between social isolation and IC domains were large, which may be attributed to measurement overlap. For example, social isolation includes self-reported difficulties with activities related to social participation and locomotion includes self-reported difficulty standing up from a chair. Given that the data are cross-sectional and temporality cannot be established, reverse causation is plausible such that less healthy functioning in IC could exacerbate food insecurity, through limiting employment opportunities or resource-generation, and increase social isolation by lowering capacity for social engagement or poorer mental health. Further research with longitudinal data is needed to examine these associations and to better understand how food insecurity and social isolation could accelerate vulnerabilities across different domains of intrinsic capacity in a cyclical pattern across adulthood.
Understanding the complex association between food insecurity and social isolation is important for clinicians as they screen and address these conditions. Food insecurity is reversible; existing nutrition and income programs have been shown to effectively reduce food insecurity in the US population [35,36]. For example, SNAP, the Supplemental Nutrition Assistance Program, is the largest federal assistance program that provides millions of Americans with monetary benefits to purchase food. SNAP has been shown to reduce very low food security by nearly 30% [36]; however, the relationship between social isolation and SNAP participation is less clear. More research is needed to understand the challenges that socially isolated adults might face in accessing and utilizing SNAP benefits, particularly in the current context where SNAP is undergoing historic budgetary cuts and structural changes [37]. Further, there is a vast network of charitable food providers, such as food pantries and congregate meal programs, which work directly to provide free groceries or meals to individuals. Congregate meal programs, funded by the Older Americans Act, provide free meals to older adults at senior centers and other community spaces are an under-utilized resource and could help to simultaneously alleviate food insecurity, provide opportunities for social engagement, and promote healthy aging for older adults [38]. Recent research has also considered the effectiveness of a variety of strategies related to “social prescribing,” the practice by medical professionals of connecting people to activities and support that improve health and wellbeing, in reducing social isolation [39,40]; evaluating effectiveness of such strategies in conjunction with efforts to alleviate food insecurity may add insight.
This study has limitations. Due to the cross-sectional design, causality cannot be established. Food insecurity, social isolation, and IC likely have cyclical effects and longitudinal data with repeated measures are needed to better understand temporality in these associations. Second, while our social isolation measure is consistent with prior studies [22,41], it is less comprehensive than other lengthier measures such as the Duke Social Support Index or the Steptoe Social Isolation Index; however, these measures are not available in NHANES [42]. Similarly, there is no widely used, standardized measure of intrinsic capacity and the proxy indicators used in the present study are unlikely to capture fully the functional range of each IC domain. Finally, there is a potential for unmeasured confounding by other unmet social needs or characteristics of the neighborhood food or social environment.
5. Conclusion
Food insecurity and social isolation are both critical social determinants of health, yet their intersection remains understudied. Our nationally representative study showed that adults with food insecurity were significantly more likely to have social isolation, with the most pronounced associations observed among middle-aged and older adults. Furthermore, food insecurity and social isolation both predicted less healthy functioning across multiple domains of intrinsic capacity for middle-aged and older adults. These findings underscore the need for clinical and public health interventions to simultaneously address food insecurity and social isolation to better promote healthy aging.
Authorship/CRedIT authorship contribution statement
Cindy Leung: conceptualization, formal analysis, writing- original draft, writing- reviewing & editing, funding acquisition. Heejin Lee: writing- reviewing & editing. Esther Friedman: writing- reviewing & editing. Laura Kubzansky: conceptualization, writing- reviewing & editing.
Ethical statement
NHANES study protocols are reviewed and approved by the NCHS Ethics Review Board. This study was conducted using publicly available, de-identified secondary NHANES data. Additional institutional review board (IRB) approval was not required.
Data statement NHANES data from this study can be accessed at: https://www.cdc.gov/nchs/nhanes/index.html.
Declaration of Generative AI and AI-assisted technologies in the writing process
No AI or AI-assisted technologies were used in the writing process.
Financial disclosures
This study was supported by the National Institutes of Health [grant numberR01AG079286].
Declaration of competing interest
The authors declare that the study was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest.
Acknowledgments
This work was supported by the National Institutes of Health [grant number R01AG079286].
Footnotes
Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.jnha.2026.100990.
Appendix A. Supplementary data
The following is Supplementary data to this article:
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