Providing nutrition supplements to institutionalized seniors with probable Alzheimer's disease is least beneficial to those with low body weight status.

Objectives: To examine whether providing a midmorning nutrition supplement increases habitual energy intake in seniors with probable Alzheimer's disease (AD) and to investigate the effects of body weight status and cognitive and behavioral function on the response to the intervention.

Design: Randomized, crossover, nonblinded clinical trial.

Setting: A fully accredited geriatric teaching facility affiliated with the University of Toronto's Medical School with a home for the aged.

Participants: Thirty-four institutionalized seniors with probable AD who ate independently.

Intervention: Nutrition supplements were provided between breakfast and lunch for 21 consecutive days and compared with 21 consecutive days of habitual intake.

Measurements: Investigator-weighed food intake, body weight, cognitive function (Severe Impairment Battery and Global Deterioration Scale), behavioral disturbances (Neuropsychiatric Inventory-Nursing Home Version), and behavioral function (London Psychogeriatric Rating Scale).

Results: Relative to habitual intake, group mean analyses showed increased 24-hour energy, protein, and carbohydrate intake during the supplement phase, but five of 31 subjects who finished all study phases completely compensated for the energy provided by the supplement by reducing lunch intake, and 24-hour energy intake was enhanced in only 21 of 31 subjects. Compensation at lunch was more likely in subjects with lower body mass indices, increased aberrant motor behavior, poorer attention, and increased mental disorganization/confusion.

Conclusion: Nutrition supplements were least likely to enhance habitual energy intake in subjects who would normally be targeted for nutrition intervention-those with low body weight status. Those likely to benefit include those with higher body mass indices, less aberrant motor problems, less mental disorganization, and increased attention.