Comparison of predictive equations for energy expenditure in pregnant women at rest and during exercise

Abstract

The regular changes that occur during pregnancy increase energy expenditure at rest and during exercise. Prediction models are practical tools that facilitate the estimation of energy expenditure. The objective of this study was to analyze the reliability of prediction models of energy expenditure for pregnant women in two situations, at rest and during light-intensity exercise, compared to indirect calorimetry. Energy expenditure was measured in 10 pregnant women during the second trimester of gestation (23.5 ± 3.7 weeks) at rest and during light-intensity treadmill walking (4 km/h) using indirect calorimetry and the prediction models proposed by Hronek (rest) and Pivarnik (exercise). The intraclass correlation coefficient (ICC) and Bland-Altman plots were used for comparison of the methods. A low correlation was observed at rest and during exercise [ICC=0.531 (-0.185; 0.814) and ICC=0.124 (-1.213; 0.653), respectively]. At rest, daily energy expenditure tended to be overestimated with increasing indirect calorimetry values. During exercise, the equation tended to underestimate the energy expenditure of pregnant women as it increased. In conclusion, the prediction models analyzed showed a low correlation with indirect calorimetry, overestimating daily energy expenditure at rest and underestimating energy expenditure during light-intensity exercise. Thus, practical and low-cost tools such as predictive equations cannot always be used safely in professional practice and care should be taken to apply them to groups with altered physiological conditions, such as pregnant women.