1. Indirect calorimetry has been used to measure resting energy expenditure (REE) and the thermogenic response to a test meal (diet-induced thermogenesis) in groups of weight-stable and weight-losing patients with gastrointestinal adenocarcinoma. Average daily intakes of energy and protein were computed from dietary assessment for the week before hospitalization. Results were compared with a control group of patients with benign gastrointestinal disease.
2. Weight-losing cancer patients had a significantly reduced mean total energy and protein intake.
3. There was no significant difference in REE between the groups when results were normalized in terms of metabolic body size (kJ/kg 0.75) and lean body mass (kJ/kg).
4. Diet-induced thermogenesis was reduced in weight-losing cancer patients.
5. It is suggested that the reduction of diet-induced thermogenesis in weight-losing cancer patients is another element of starvation adaptation, subsequent to their weight loss, and that altered thermogenesis does not contribute to the weight loss seen in cancer cachexia.