Adult energy requirements predicted from doubly labeled water.

Background: Estimating energy requirements forms an integral part of developing diet and activity interventions. Current estimates often rely on a product of physical activity level (PAL) and a resting metabolic rate (RMR) prediction. PAL estimates, however, typically depend on subjective self-reported activity or a clinician's best guess.

A computational model to determine energy intake during weight loss.

Background: Energy intake (EI) during weight loss is difficult and costly to measure accurately.

Objective: The objective was to develop and validate a computational energy balance differential equation model to determine individual EI during weight loss.

Design: An algorithm was developed to quantify EI during weight loss based on a validated one-dimensional model for weight change.