Dietary advice for illness-related malnutrition in adults

Illness-related malnutrition has been reported in 10% to 55% of ill people in hospital and the community in areas of food sufficiency. Dietary advice encouraging the use of energy- and nutrient-rich foods rather than oral nutritional supplements has been suggested for managing illness-related malnutrition.

To examine evidence that dietary advice to improve nutritional intake in adults with illness-related malnutrition improves survival, weight and anthropometry; to estimate the size of any additional effect of nutritional supplements given in combination with dietary advice.

Relevant publications were identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Additional studies were sought by contacting dietitians, clinicians and the manufacturers of nutritional supplements. Last search: September 2007

Randomised controlled trials of dietary advice in people with illness-related malnutrition compared with:(1) no advice;(2) oral nutritional supplements; and(3) dietary advice plus oral nutritional supplements.

Two authors independently assessed trial eligibility, methodological quality and extracted data.

Thirty-six studies (37 comparisons) met the inclusion criteria with 2714 randomised participants. Twelve trials (comparing dietary advice plus supplements if required with no advice) identified during searching are included as a separate comparison. Follow up ranged from 18 days to 24 months. No comparison showed a significant difference in mortality. There are several significant results for change in weight and other nutritional indices favouring nutritional intervention, but the precise contributions of the different strategies have yet to be determined. It is uncertain whether nutritional supplements and dietary advice produce the same effects. There was insufficient evidence to draw conclusions about clinical outcomes and cost. Few data were available for other outcomes.

This review highlights the lack of evidence for the provision of dietary advice in managing illness-related malnutrition. Dietary advice plus nutritional supplements may be more effective than dietary advice alone or no advice in enhancing short-term weight gain, but whether this is sustainable, or whether survival and morbidity are improved remains uncertain. A large adequately-powered randomised controlled trial is needed comparing the efficacy of different therapies to increase dietary intake in people with illness-related malnutrition and examining the impact of this on clinical function and survival.