Undernutrition is a health challenge due to an expanding older population. The aims of the study were to assess the prevalence and determinants of undernutrition and, associated factors of low muscle and high fat mass among older men and women in the Colombo district of Sri Lanka. A cross sectional study was conducted using a multistage cluster sampling technique. Undernutrition was defined based on anthropometry and body composition assessed using bio-electrical impedance. Sex-specific multivariable logistic regression analyses were conducted. Of 800 participants (30.6% men), 35.3% were undernourished. The factors significantly associated with undernutrition among older women were hypertension with an adjusted odds ratio (aOR) (1.97; 1.36–2.88) and musculoskeletal disabilities aOR (2.19; 1.36–3.53). Among women, age ≥ 70 (1.79; 1.18–3.34) and diabetes (1.77; 1.10–2.84) were associated with low muscle mass and age ≥ 70 (2.05; 1.21–3.47), diabetes (2.20; 1.35–3.59) and disability in chewing (2.39; 1.30–4.40) were associated with high fat mass. Among men, age ≥ 70 years, no/up to grade 5 education, diabetes, visual disability, little/no responsibility in food shopping and not getting nutritional advice from media were associated with reduced odds of low muscle mass and no/up to grade 5 school education, disability in chewing and little/no responsibility in food shopping were associated with reduced odds of high fat mass. Undernutrition among older people is common in Sri Lanka. We have identified key factors associated with low muscle mass and high fat mass in this setting. Given the potential consequences of these conditions, our study provides potential targets for prevention of undernutrition and sarcopenic obesity.

Low-cost educational interventions to improve dietary pattern is a pragmatic solution to prevent undernutrition in low- and middle-income countries. A prospective nutritional education intervention was conducted among older adults aged 60 years or above with undernutrition with 60 people in each intervention and control group. The objective was to develop and evaluate the efficacy of a community-based nutrition education intervention to improve the dietary pattern of older adults with undernutrition in Sri Lanka. The intervention consisted of two modules to improve the diversity, the variety of diet, and the serving sizes of food consumed. The primary outcome was the improvement of the Dietary Diversity Score (DDS) and the secondary outcomes were the Food Variety Score and Dietary Serving Score, which was assessed using the 24 h dietary recall. The mean difference in scores between the two groups was compared using the independent sample t-test at baseline, two weeks and three months post-intervention. Baseline characteristics were comparable. After two weeks, only the difference in DDS between the two groups was statistically significant (p = 0.002). However, this was not sustained at three months (p = 0.08). This study concludes that nutrition education interventions have the potential for short-term improvement in dietary patterns in older adults in a Sri Lanka setting.