Background <p>Provision of vascular imaging results has been investigated to prompt changes towards healthy lifestyle behaviours, but effects on body composition and muscle health are unknown.</p> Aim <p>This secondary analysis of a 12-week parallel-group randomised controlled trial (RCT) aims to explore body composition and muscle health effects of providing healthy lifestyle education (Ed) with and without abdominal aortic calcification (AAC) results.</p> Methods <p>A total of 240 Australian community-dwelling older men and women (mean ± SD age 68 ± 5 years; 58% female; 57.1% with evidence of AAC) were randomised to AAC + Ed (<i>n</i> = 121) or Control + Ed (<i>n</i> = 119). Linear mixed models were used to compare between-group changes in body composition (dual-energy X-ray absorptiometry), grip strength, and subjective physical function.</p> Results <p>In total, 226 (94%) participants completed the trial. Provision of AAC results with lifestyle education provided no benefits to body composition, grip strength or physical function, compared to education alone. Exploratory analyses within the AAC + Ed group showed that those with evidence of AAC at baseline had greater declines in fat mass (net difference in change [95% CI] -0.6 [-1.0, -0.1] kg, <i>p</i> = 0.016) and visceral adipose tissue (-31 [-61, -1] g, <i>p</i> = 0.044) compared to those without evidence of AAC.</p> Conclusions <p>Providing AAC results with healthy lifestyle education did not improve body composition or muscle health in older adults, compared to education alone. Provision of AAC results to those with evidence of AAC at baseline did improve total and visceral fat mass compared to those without evidence of AAC, but these findings require further investigation.</p> Trial registration <p>Australian New Zealand Clinical Trial Registry (anzctr.org.au); registration number ACTRN12618001087246; registered 28/06/2018.</p>