Obesity Tissue: Composition, Energy Expenditure, and Energy Content in Adult Humans

Phoenix Hwaung, Anja Bosy-Westphal, Manfred J. Muller, Corinna Geisler, Moonseong Heo, Diana M. Thomas, Samantha Kennedy, Steven B. Heymsfield

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

Objective: Chronic positive energy balance leads to obesity, and the “excess” weight is usually described as consisting solely of adipose tissue (AT) or its two components, fat and fat-free mass (nonfat cell mass, extracellular fluid). This study aimed to clarify the nature of “obesity” tissue. Methods: A total of 333 adults had AT, skin, skeletal muscle, bone, heart, liver, kidney, spleen, brain, and residual mass measured or derived using magnetic resonance imaging and dual-energy x-ray absorptiometry. First, associations between these components and AT were examined by developing multiple regression models. Next, obesity-tissue composition was developed by deriving mean component mass differences between participant groups with normal weight (BMI < 25 kg/m2) and those with obesity (BMI > 29.9 kg/m2); respective resting energy expenditures and metabolizable energy and protein contents were calculated. Results: AT significantly predicted organ-tissue mass in 17 of 18 multiple regression models. In addition to AT and skeletal muscle, the following associations were found: skin, liver, and bone were main contributors to obesity-tissue composition; liver, kidneys, and heart to resting energy expenditure; and skin, liver, and bone to metabolizable energy and protein contents. A pronounced sexual dimorphism was present in all three models. Conclusions: Obesity is characterized not only by excess AT but by increases in the masses of other “companion” organs and tissues and their related metabolic properties.

Original languageEnglish (US)
JournalObesity
DOIs
StatePublished - Jan 1 2019

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ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Nutrition and Dietetics

Cite this

Hwaung, P., Bosy-Westphal, A., Muller, M. J., Geisler, C., Heo, M., Thomas, D. M., Kennedy, S., & Heymsfield, S. B. (2019). Obesity Tissue: Composition, Energy Expenditure, and Energy Content in Adult Humans. Obesity. https://doi.org/10.1002/oby.22557