title: Resting energy expenditure-fat-free mass relationship: new insights provided by body composition modeling.
abstract: The relationship between resting energy expenditure (REE) and metabolically active fat-free mass (FFM) is a cornerstone in the study of physiological aspects of body weight regulation and human energy requirements. Important questions, however, remain unanswered regarding the observed linear REE-FFM association in adult humans. This led us to develop a series of REE-body composition models that provide insights into the widely used simple linear REE-FFM prediction model derived experimentally in adult humans. The new models suggest that the REE-FFM relationship in mammals as a whole is curvilinear, that a segment of this function within a FFM range characteristic of adult humans can be fit with a linear equation almost identical to that observed from a composite review of earlier human studies, and that mammals as a whole exhibit a decrease in the proportion of FFM as high metabolic rate organs with greater FFM. The present study thus provides a new approach for examining REE-FFM relationships, advances in a quantitative manner previously observed albeit incompletely formulated REE-body composition associations, and identifies areas in need of additional research.
authors.affiliation: Obesity Research Center, St. Luke's-Roosevelt Hospital, College of Physicians and Surgeons, Columbia University, New York, New York 10025, USA. ZW28@Columbia.edu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Heshka
authors.forename: D
authors.initials: D
authors.lastname: Gallagher
authors.forename: C N
authors.initials: CN
authors.lastname: Boozer
authors.forename: D P
authors.initials: DP
authors.lastname: Kotler
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
mesh_terms: D000465:Algorithms; D001823:Body Composition / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D012146:Rest / Q000502:physiology*