title: High respiratory quotient is associated with increases in body weight and fat mass in young adults.
abstract: Metabolic disturbances, such as reduced rates of fat oxidation (high respiratory quotient (RQ)) or low energy expenditure (low resting metabolic rate (RMR)), may contribute to obesity. The objective was to determine the association between a high RQ or a low RMR and changes in body weight and body composition over 1 year.
  
  
  
  We measured RQ and RMR in 341 adults using indirect calorimetry, along with body weight/body composition using dual-energy X-ray absorptiometery, energy expenditure using an arm-based activity monitor and energy intake using dietary recalls. Participants were classified into low, moderate or high RQ and RMR (adjusted for age, sex, race and body composition) groups according to tertiles by sex. Follow-up measurements were completed every 3 months.
  
  
  
  Individuals with a high RQ had larger gains in body weight and fat mass compared with individuals with a low/moderate RQ at month 3, and increases in fat mass were more than double among individuals with a high RQ at 12 months (1.3±3.0 vs 0.6±3.7 kg, P=0.03). Individuals with a low RMR did not gain more body weight nor fat mass compared with individuals with a moderate/high RMR.
  
  
  
  The primary finding is a high RQ is predictive of gains in body weight and fat mass over a 12-month period among young adults, with changes occurring as soon as 3 months. In addition, a low RMR was not associated with gains in body weight or fat mass over the same period.
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, IA, USA.
authors.forename: R P
authors.initials: RP
authors.lastname: Shook
authors.affiliation: School of Public Health, University of West Virginia, Morgantown, WV, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Hand
authors.affiliation: Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Paluch
authors.affiliation: Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
authors.forename: X
authors.identifier: 0000-0001-8246-0999
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
authors.forename: R
authors.initials: R
authors.lastname: Moran
authors.affiliation: Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.|Department of Family and Preventive Medicine, University of South Carolina, Columbia, SC, USA.|South Carolina Statewide Cancer Prevention and Control Program, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Hébert
authors.affiliation: Department of Health and Physical Activity, Physical Activity and Weight Management Research Center, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Jakicic
authors.affiliation: Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.|Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
authors.forename: S N
authors.initials: SN
authors.lastname: Blair
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity; D000328:Adult; D001481:Basal Metabolism; D001835:Body Weight; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism*; D012119:Respiration; D055815:Young Adult