Seasonal variation in dietary diversity and food variety scores among an indigenous Karen population in western Thailand: A cross-sectional study

Objective: This study compared dietary diversity and nutrient adequacy across age groups and seasons within an indigenous Karen community. Design: Cross-sectional survey. Setting: Dietary intake was assessed using a single-day 24-h dietary recall among Karen community members living in two villages of Laiwo subdistrict, Sangkhlaburi district, Kanchanaburi province, Thailand. Participants: In total, 312 Karen people participated during the rainy season and 344 during the dry season, including school-age children (6-12 years), working-age people (19-59 years) and older people (≥ 60 years). Results: Dietary diversity scores and food variety scores significantly differed across age groups for both seasons. However, seasonal dietary diversity score differences were not observed within any group, except for the food variety scores of school-age children. Over 70 % of participants in all age groups had inadequate intake of key micronutrients - Ca, Fe, vitamin A, vitamin C, Zn, vitamin B6 and vitamin B12 - as indicated by nutrient adequacy ratios < 0·75. Moderate to strong positive correlations between dietary diversity scores and nutrient adequacy ratios for energy, vitamin B2, vitamin C, niacin and mean adequacy ratio (r = 0·418-0·691, P < 0·001) were observed exclusively in the dry season and across all age groups. Conclusions: Among the Karen people, who are also facing triple burden malnutrition, dietary diversity is limited, micronutrient inadequacy is prevalent and overall dietary quality is insufficient despite frequent vegetable consumption. Findings highlight the need to address systemic challenges related to food variety and to promote education on appropriate food quantities, preparation methods and sustainable traditional food systems to improve nutrition.