Special considerations for nutritional studies in elderly.

The elderly population is increasing and it is well documented that may present some health problems related to nutritional intake. Both mental and physical impairments in the elderly may need specific adaptations to dietary assessment methods. But all self-report approaches include systematic and random errors, and under-reporting of dietary energy intake is common. Biomarkers of protein intake, as 24 hours urinary Nitrogen, may not be useful in elderly patients because of incontinence problems. Some micronutrients, like vitamin B12, have special importance in the elderly population. Also, measurement of fluid intake is also critical because elderly population is prone to dehydration. A detailed malnutrition status assessment should be included in the geriatric dietary history, and assessment. Body mass index (BMI) is not useful in the elderly, and it is important to evaluate functional status. Gait speed, handgrip strength using hand dynamometry can be used. Body Shape Index (ABSI) appears to be an accurate measure of adiposity, and is associated with total mortality. Further research is needed to clarify the best and simple methods to accurately estimate food and beverage fluid intake in the elderly population, and to evaluate nutritional and hidration status.