Your skin may offer clues about how many fruits and vegetables you eat

By Dr. Liji Thomas, MDReviewed by Lauren HardakerAug 30 2026

Could a simple skin measurement offer clues about what people eat? Researchers examined how diet, skin color, ethnicity, and body composition shape the signal detected by reflectance spectroscopy.

Review: Examining Demographic Variables Associated with Fruit and Vegetable Intake and Skin Yellowness. Image Credit: New Africa / Shutterstock

A preliminary study published in the journal Nutrients found that skin yellowness, measured using reflectance spectroscopy, could serve as a useful objective proxy for fruit and vegetable intake when skin color and other individual characteristics are accounted for.

Background

Adequate fruit and vegetable (FV) intake is key to good health. Low FV consumption has been linked to about 3.9 million deaths worldwide, besides multiple chronic conditions. However, global statistics indicate that most adults fail to meet recommended targets for these foods.

For instance, only 4% of adults in Australia eat enough FV.

Besides their macronutrient composition, FV provide phytonutrients, including carotenoids, fat-soluble pigments found in yellow, red, and orange FV. These compounds have antioxidant and anti-inflammatory properties, and their adequate intake is associated with a reduced risk of cancer, type 2 diabetes, stroke, heart disease, and death from any cause.

A typical diet includes foods containing around 40 different carotenoids, the most abundant being α-and β-carotene, β-cryptoxanthin, lycopene, lutein, and zeaxanthin. Carotenoids are stored in the skin and in adipose tissue.

Factors that affect skin carotenoid concentration include dietary intake, age and sex, body mass index (BMI), body fat, use of carotenoid supplements, smoking, and sun exposure. Increased FV intake is linked to higher levels of skin carotenoids, which serve as an objective, time-efficient biomarker of FV intake.

Carotenoid intake or body levels are estimated from self-reported dietary assessments, blood or urine testing, and spectroscopy-measured skin yellowness. Notably, dietary intake estimates derived from validated assessments, such as the Australian Eating Survey (AES), have been positively associated with skin yellowness.

However, less is known about how spectroscopy-based yellowness varies with FV intake, as measured by food frequency questionnaires (FFQs), across diverse age, sex, and ethnic groups. The current study aimed to evaluate this association across various demographic characteristics and self-reported skin color.

Study characteristics

The study included an exploratory, cross-sectional, convenience sample of 137 adults from Newcastle, New South Wales, Australia, with a study period from October 2023 to June 2025. Most participants were female and Caucasian, with an average age of 38.6 years. They filled in the AES, from which the researchers derived the Australian Recommended Food Score (ARFS) diet quality scores for fruit and vegetable intake, total score, and ‘other’ score.

They then calculated the intake of five individual carotenoid categories and the total carotenoid intake. Skin reflectance spectroscopy was performed to calculate skin yellowness at four body sites with lower sunlight exposure, with each site measured three times to obtain the mean.

Anthropometric measurements were also obtained. Multiple linear regression models were then used to identify factors associated with skin yellowness.

On average, participants met the recommended daily intake of fruit (2 servings per day) but not that of vegetables (5-6 servings per day), with a mean of 4.4 servings. Of the Caucasians, the largest proportion self-reported having a very fair skin tone (43.8%). Among Asian participants, the largest proportion (34.4%) reported a light olive skin tone.

Skin color and skin yellowness

Fair skin did not differ significantly from very fair skin in measured yellowness, and no significant association was found between skin yellowness and age, sex, or season. However, skin yellowness was higher in light olive skin compared to very fair skin. Dark olive/brown skin was also associated with higher yellowness in three of the four models, although few participants reported these skin tones. This suggests that natural differences in skin color may affect the interpretation of such measurements.

Dietary intake and skin yellowness

Fruit intake and combined FV intake were separately associated with skin yellowness, with each additional serving associated with 0.30 and 0.10 units higher skin yellowness, respectively.

Total carotenoid intake was associated with skin yellowness, with each SD higher total carotenoid intake associated with 0.41 units higher skin yellowness. However, only beta-carotene was associated with skin yellowness.

ARFS FV or ‘other’ categories were not associated with skin yellowness. Conversely, ARFS total and ARFS fruit were positively associated with skin yellowness.

The authors suggest that the lack of association between skin yellowness and vegetable intake, despite its association with fruit and FV intake, could be due to inadequate vegetable intake or to differences in carotenoid bioavailability depending on the method of preparation and the presence of dietary fat.

Ethnicity and skin yellowness

Self-reported Asian ethnicity was associated with higher skin yellowness than Caucasian ethnicity. FV intake, ARFS ‘other’, ARFS FV, and total carotenoids were also associated with skin yellowness in models that included ethnicity instead of skin color.

The association between skin yellowness and ethnicity may be better explained by skin color, according to the authors, but this requires further study.

Body fat and skin yellowness

Higher body fat percentage was associated with lower skin yellowness, but skin yellowness was not associated with fat intake or energy intake.

Prior research has demonstrated the anti-inflammatory properties of carotenoids, in contrast to the pro-inflammatory effects of high body fat percentage. This finding was consistent with previous studies reporting lower carotenoid concentrations with greater adiposity.

The authors suggest that this may be due to oxidative stress associated with adiposity, leading to reduced blood carotenoid levels and, consequently, reduced deposition in the skin.

The authors caution that these are exploratory findings that warrant further study. They suggest that, based on these results, intrinsic factors such as ethnicity and skin color and extrinsic factors such as dietary intake influence skin yellowness and may be linked to skin carotenoid deposition.

Skin yellowness and sex

In contrast, skin yellowness was not associated with sex, which the authors suggest may partly reflect that they rescaled body fat to account for differences in minimum body fat percentages between the sexes.

Limitations

This was an exploratory cross-sectional study and therefore cannot establish causality. The use of a convenience sample, self-reported dietary assessment, skin color, and a small proportion of participants reporting dark olive or brown skin are among the limitations of the study that could reduce its generalizability.

The small sample also meant that ethnicity and self-reported skin color could not be included in the same model due to multicollinearity, limiting the ability to determine which factor drove the observed association. The main models explained 38–41% of the variance in skin yellowness, with dietary variables providing only modest improvements in model fit.

Conclusion

Taken together, the findings suggest that skin yellowness is associated with both combined fruit and vegetable intake and fruit intake alone, after adjusting for skin color, age, and sex. It was also associated with body fat percentage. This supports the use of skin yellowness as a non-invasive, objective proxy for FV intake.

Future studies should use larger and more diverse samples to explore the relationship between skin yellowness and these demographic attributes.