This secondary analysis examined dietary intake and body composition data from a nine-month nutritional intervention designed to prevent weight loss in older adults with dementia in a long-term care setting. There were no significant differences in dietary intake and body composition with nutritional intervention (n = 34), however there was a decrease in fat intake. The proportion of dietary intake from supplements increased, and the dietary intake from food sources decreased, with nutritional intervention. Mental status, level of agitation, and functional abilities were associated with dietary intake. There was no significant difference in body weight between the intervention and standard care (n = 47) groups. The findings suggest that the period of intervention may not have been long enough and that this regimen reduced food intake. Future studies of longer duration are necessary to determine appropriate supplementation and nutritional intervention to prevent weight loss in older adults living with dementia in long-term care facilities.