Objective: To evaluate regular use of a liquid nutrition supplement by subjectively healthy elderly persons in terms of body mass index, nutrient intake, selected biochemical parameters, and perceived quality-of-life changes, and to identify advantages and limitations of use.
Design: A 16-week intervention study in which subjects were assigned randomly to either a supplemented group or a control group and compared in terms of intergroup and intragroup differences in weight, food intake, blood values, and quality-of-life indexes. Adherence to protocol was monitored by monthly visits with an interviewer and food intake records.
Subjects/setting: Seventy-one independent living, older Canadian adults (mean age = 70 +/- 7 years) consuming on average less than 4 servings of fruit and vegetables daily and a supplement-free diet before the study. Subjects were without functional limitations and did not require therapeutic diets or medical treatments that affect nutritional status. Data were collected in home interviews. Blood for analysis was obtained from a subsample of 36 subjects.
Intervention: Inclusion of six 235-mL cans of liquid nutrition supplement weekly into the self-selected dietary patterns of the supplemented group.
Statistical analysis: Results were analyzed by Student t tests or Wilcoxon rank sum test, analysis of variance, and multiple stepwise regression.
Results: Body mass index, energy intake, and consumption of fruit and vegetables did not change throughout the study. In the supplemented group, statistically significant increases occurred from baseline to termination of the study in these nutrients: protein, calcium, iron, magnesium, and folate. Serum albumin, folate, ferritin, hemoglobin, and zinc values were within the normal range for the supplemented and control groups. Scores for the Medical Outcomes Study 36-Item Short-Form Health Status scales increased for the supplemented group from baseline to termination for vitality and general health perception. Values for the General Well-Being Questionnaire improved for anxiety and general well-being. Of the dietary predictors, folate intake explained the most variance for vitality and for general well-being, 8.6% and 14.2%, respectively.
Applications: A liquid nutrition supplement could be recommended to the elderly when energy maintenance and increases in nutrient intake are necessary and convenience is an important consideration. Dietetics professionals should address the issues of affordability of the supplement, the role of food in achieving nutritional adequacy, and overall quality of life of clients. Folate intake as a predictor of perceived general well-being and vitality requires further investigation.