Seven-item scale proves reliable for measuring body functionality appreciation in Mexican adults over 50

A new validation study from Mexico reports that the Functional Appreciation Scale, a brief seven-item questionnaire measuring how much people value and respect what their bodies can do, works well among middle-aged and older Mexican adults. The research, published in Discover Aging, found that the scale kept its original single-factor structure in this population, showed acceptable reliability, and behaved consistently across men and women. Because no validated version of the instrument had previously existed for the Mexican population, the authors describe the work as a first step toward making the tool available for gerontological research in the country.

Functional appreciation, as defined by the researchers who originally developed the scale, is the valuation of physical functionality: respecting and praising the body for what it can do, beyond mere awareness of appearance. It concerns internal processes, bodily senses and perceptions, creative endeavours, communication with others, and self-care. Although functionality may be altered by illness, injury, structural differences, or aging itself, esteem for one’s own body refers to functionality regardless of its limitations. The original Functional Appreciation Scale, designed by Alleva and colleagues, consists of seven items answered on a five-point agreement scale, with higher scores indicating greater functional appreciation, and is intended for adults aged 18 to 75.

The motivation for testing the scale in Mexico rests on demographic and health context. The proportion of the global population aged 65 and older has been increasing significantly, and in Mexico the population aged 50 and older totals 25.9 million, of whom 45.6 percent are men and 54.4 percent are women. Older adults represent 12.8 percent of the total population, with an annual increase of 1.3 percent. According to the study, half of older adults have some form of sensory-motor, cognitive, or functional limitation in activities of daily living, and the prevalence of frailty stands at 11 percent among people aged 65 and older, where it is associated with low socioeconomic status, cognitive decline, falls, sarcopenia, malnutrition, and depression. The authors argue that evidence-based tools promoting quality of life from a body image perspective are therefore imperative, noting that body image in older adults is characterized by placing greater importance on physical capacity rather than physical appearance.

To carry out the validation, the team conducted a quantitative study with a non-experimental, instrumental design, using a purposive, non-probabilistic sample recruited through snowball sampling between February and June 2024. Participants were drawn from acquaintances and relatives of students in the gerontology bachelor’s degree program at the Autonomous University of the State of Hidalgo, and the study received ethics approval from the same institution. A total of 357 participants took part, divided into two subsamples. The first, 146 people, was used for exploratory factor analysis; the second, 211 people, was used for confirmatory factor analysis. The exploratory group was 2.5 percent middle-aged and 97.9 percent older adults, aged 51 to 88 with a mean age of 70.24, comprising 95 women and 51 men. The confirmatory group was 2.8 percent middle-aged and 97.1 percent older adults, aged 50 to 96 with a mean age of 68.5, comprising 130 women and 81 men. All participants were over 50 and could read and write, or were assisted by a caregiver or interviewer. Individuals with terminal illness or cognitive impairment, as reported by a caregiver or detected by an interviewer with a bachelor’s degree in gerontology, were excluded.

For the Mexican version of the scale, the researchers used the Spanish adaptation prepared for the Colombian population, verifying comprehension of the instructions, items, and response options among all participants since administration was face-to-face and individual. A pilot test was conducted before the main assessment to ensure semantic equivalence and conceptual understanding, including a cognitive pre-test with a convenience sample of five participants. Alongside the target scale, participants completed a battery of measures including the Body Appreciation Scale-2, the Gratitude Questionnaire-6, and the Rosenberg Self-Esteem Scale, all of which have previous Mexican validations. Data were collected individually through face-to-face interviews with those who reported being unable to read or use a mobile device, and responses were kept anonymous to control for social desirability.

The statistical results supported the scale’s original design. In the exploratory analysis, feasibility requirements were met with a Kaiser-Meyer-Olkin coefficient of 0.85 and significant Bartlett’s sphericity, and a parallel analysis suggested a single factor. No inter-item correlations exceeded the critical threshold of 0.80, with the highest association at 0.66, indicating that the indicators are complementary rather than redundant. The exploratory factor analysis confirmed a unifactorial structure, with items loading between 0.85 and 0.92 on the factor, which explained 86.42 percent of the variance. Fit indices were favourable, including a goodness-of-fit index of 0.997 and a root mean square error of approximation of 0.043. The confirmatory analysis on the second subsample of 211 participants also produced an adequately fitted model, with a non-significant chi-square, comparative fit index of 0.996, goodness-of-fit index of 0.998, and root mean square error of approximation of 0.045, whose upper confidence limit of 0.061 fell below the 0.10 threshold. Item coefficients between 0.63 and 0.76 were retained, and item 6 showed the highest error variance, consistent with its lower factor loading.

Reliability estimates were acceptable across both samples. Internal consistency of the scale as a whole ranged from 0.87 to 0.91 using Cronbach’s alpha and McDonald’s omega coefficients. Broken down by sex, men obtained adequate coefficients in both samples, with omega values of 0.89 and 0.88, while women showed values above 0.90 in both samples. The authors note that these figures are consistent with the coefficients reported in previous validations of the scale in other countries, which have ranged from 0.80 to 0.97, and that the scale has been adapted in Latin America, Europe, and Asia across different age groups, including older adults.

The study also examined whether the scale functions equivalently for men and women. Using a multi-group confirmatory approach on a split-half of the second subsample, the configural invariance model exhibited an acceptable fit, and the change in the comparative fit index for metric invariance fell below the conventional 0.010 cut-off, confirming that the factor loadings of the seven items are equivalent across genders. However, the authors report that strict invariance was not observed, with a change in comparative fit index of 0.058, and they caution that absolute RMSEA values fell within suboptimal thresholds, a divergence they attribute to the tendency of RMSEA to overestimate approximation error in models with few degrees of freedom and moderate sample sizes. Comparing scores directly, a Welch’s t-test found no statistically significant difference between women, who averaged 31.1, and men, who averaged 30.8, with an effect size of 0.072, indicating that the perception of functionality behaves similarly regardless of gender in this sample.

Convergent validity results showed statistically significant positive correlations of moderate magnitude between functional appreciation and the related psychological constructs measured in the battery: body appreciation at 0.33, gratitude at 0.41, and self-esteem at 0.48. The authors observed that the association with body appreciation was weaker than in previous studies, which they suggest may be because those samples included younger populations, in whom self-worth takes on a different meaning compared to the perspective shaped by the aging process. The study’s limitations are acknowledged explicitly: only convergent validity was assessed, with divergent validity and test-retest reliability left for future work; the sample did not include institutionalized adults; sociodemographic data such as educational level, health status, and functional independence were not integrated; and the sample sizes were low compared to other studies, which may have influenced the results. The conclusion drawn by the authors is measured: the Mexican version of the scale confirmed the unidimensionality of the original instrument and proved to have adequate psychometric properties for middle-aged and older adults, serving as a preliminary step for gerontological psychology research into how older adults perceive and accept their bodies.

Subject of Research: Validation of the Functional Appreciation Scale in middle-aged and older Mexican adults

Article Title: Psychometric properties of the Functional Appreciation Scale (FAS) in middle-aged and older adults in Mexico

Article References: Flores-Pérez, C. J., Bosques-Brugada, L. E., Ledesma-Amaya, L. I., Lopéz-Pontigo, L., Franco-Árcega, A., Sánchez-Salinas, A., & Guzmán-Saldaña, R. (2026). Psychometric properties of the Functional Appreciation Scale (FAS) in middle-aged and older adults in Mexico. Discover Aging, 1(1), Article 7. https://doi.org/10.1007/s44518-026-00007-0

Image Credits: AI Generated

DOI: 10.1007/s44518-026-00007-0

Keywords: functional appreciation, body image, psychometric validation, older adults, Mexico, aging, scale reliability, confirmatory factor analysis, gender invariance, self-esteem, gratitude, gerontology