The physical activity energy expenditure mainly refers to the part of the body energy which is used for muscle contraction to mechanical work. With the improvement of living standards, people’s diet structure has changed enormously. Basing on it, the three-dimensional acceleration monitoring system to monitor the physical activity energy expenditure and daily actions is proposed in the paper. Hardware Design and The mechanism of accelerometer assessing movement energy were also proposed in the paper. The system is based on three-dimensional acceleration transducer MMA 7260QT and micropro...