In clinical practice and in metabolic research, it is often necessary to determine whether body-weight has changed, and if so by how much, during the period of observation. Unless the changes are gross, single measurements at the beginning and the end of the period may be misleading because the trend of weight is obscured by rapid fluctuations from day to day. 'These fluctuations may be quite l...

An imbalance between energy intake and energy expenditure will lead to a change in body weight (mass) and body composition (fat and lean masses). A quantitative understanding of the processes involved, which currently remains lacking, will be useful in determining the etiology and treatment of obesity and other conditions resulting from prolonged energy imbalance. Here, we show that a mathemati...

The composition of weight change has a large impact on energy balance calculations. Composition of long-term weight change interventions is well-documented, but information on short-term weight change under unrestricted free-living conditions is limited. The composition and energy density of the changes in body weight during 2-week free-living conditions were analyzed in adults from two cohorts...