Challenges to rebuilding the US food pyramid.

PURPOSE OF REVIEW: Twelve years have passed since the US Department of Agriculture introduced the Food Guide Pyramid as a single visual expression of the major food groups and their relative amounts in a healthy diet. Unfortunately, no regular review has been conducted to incorporate new knowledge. Some feel that the pyramid format is too limited for modern use, while others wish it to continue with new information. It seems timely to review what features of the pyramid design have been useful over past years and how it can be improved with new concepts while maintaining ease of understanding by the average consumer. RECENT FINDINGS: Examples are presented of adapting the pyramid to diets promoted by a special group or to support particular dietary beliefs, in contrast to the goal of seeking a single standardized format. Inherent limitations of the pyramid format are discussed. One proposal is discussed which seeks to redesign the pyramid into a modern educational tool presenting current concepts supported by recent studies and outcomes data. Popular beliefs about what is a healthy diet have perhaps never been as varied as now. This is partly due to sharply differing opinions about which highly publicized weight-loss diet is most effective. SUMMARY: The educational benefits of the pyramid format need objective study in view of the inherent limitations of that configuration. Only when the specific visual advantages for the consumer are shown can a decision be made as to the benefit of major new efforts to construct a single modern pyramid.

Nutritional frailty, sarcopenia and falls in the elderly.

PURPOSE OF REVIEW: There is currently intense interest in understanding why certain elderly individuals become frail and disabled with age whereas others do not. Is frailty the result of an acceleration of normal aging processes or is it the result of chronic medical conditions that are superimposed on the conventional mechanisms of aging? The clinical problem of falls has long been recognized as a threat to some elderly individuals, but too often is not considered worthy of objective study. The factors underlying falls are now being investigated as part of the increasing attention being paid to the evolution of frailty in the elderly. RECENT FINDINGS: Frailty in the elderly has been given many names, but increasing efforts are now being made to define frailty in a standardized way that would allow more objective study. The frail elderly patient usually shows loss of both neurological and muscle function. Falls in the elderly are an example in which deterioration may be present in both functions. Methods are being developed to separate the loss of muscle capacity from the associated loss of central and peripheral neurological function involved in gait and balance. SUMMARY: The definition of frailty has been centered around the onset of accelerated weight loss with an associated decrease of mass and strength of skeletal muscle. New studies are discussed that extend this definition. Methods for a more detailed analysis of the physiological and metabolic deficits leading to falls in the elderly may provide a better understanding of frailty in general.