Effect of liquid dietary supplements on energy intake in the elderly

Undernutrition is a risk factor for increased mortality in older adults. Therapeutic intervention includes the administration of liquid dietary supplements.

We investigated the effect of liquid dietary supplements on satiation, satiety, and energy intake in older adults.

This study had 2 phases in a within-subject, repeated-measures design. The energy intake of 15 elderly (aged >70 y) and 15 younger (aged 20-40 y) healthy subjects was measured after 4 liquid preloads: water, high fat, high carbohydrate, and high protein. The preloads were administered within 5 min of a test meal in phase 1 and >or=60 min before the test meal in phase 2. Palatability, fullness, and hunger were assessed by using visual analogue scales.

Mean energy consumption of the test meals was significantly lower in the older than in the younger subjects (P = 0.001), as was mean macronutrient consumption of fat and carbohydrate (P = 0.002 and 0.001, respectively). Mean energy intake and macronutrient consumption were higher in phase 2 than in phase 1 in both older and younger subjects (P < 0.05). Satiety lasted longer in older than in younger subjects after the high-protein and high-fat preloads (P = 0.001).

In the elderly, administration of dietary supplements between meals instead of with meals may be more effective in increasing energy consumption.