Assessement of resting energy expenditure of obese patients: comparison of indirect calorimetry with formulae.

Background & Aims: Determining the caloric expenditure of overweight (Body mass index - BMI from 25-29.9 kg/m(2)) or obese (BMI> or =30 kg/m(2)) patients is a difficult task. The importance of the measurement using indirect calorimetry (IC) is to avoid the administration of an inadequate caloric load, which can increase clinical morbidity.

Can measured resting energy expenditure be estimated by formulae in daily clinical nutrition practice?

Purpose Of Review: To recognize the fundamental factors that alter energy expenditure on a daily basis and the impact they have on the measurement of caloric consumption by the human body, through respiratory indirect calorimetry, and thus to try to determine which predictive equation best correlates with total energy expenditure generated from energy measurements.

Recent Findings: The most important compartment of the body, for its metabolic activity and influence upon resting metabolic rate, is fat-free mass. Other variables affecting energy expenditure are sex, weight, height, age, body surface area, fat mass and ethnicity.