Energy expenditure and requirements in cancer patients
In most nutritional studies of cancer patients, dietary intakes have been compared with
the recommended daily intake (RDA) for healthy subjects (29). Such comparisons
may be relevant but are plagued by the important question: Is energy expenditure, and
thus requirement, higher in cancer patients than in non-cancer individuals?
Total energy expenditure (TEE) involves REE (approximately 70%), voluntary energy
expenditure (25%) and energy expended in digestion (5%) (13). REE is defined as the
metabolic rate in kilocalories (kcal) per day of a postprandial individual, more than
two hours after a meal, lying in bed in a comfortable environment. REE may be
measured by the doubly labelled water method (30), by indirect calorimetry (31) or
calculated by the equations of Harris and Benedict (H&B), (31, 32) or the World
Health Organisation (33).