Physiological and biochemical variables asssociated with body fat loss in overweight women

N. L. Keim, T. F. Barbieri, M. Van Loan

Research output: Contribution to journalArticle

6 Scopus citations


During a weight loss study conducted on a metabolic unit, five women lost an average of 8.7 ± 0.7 kg of body fat mass (FM) with a 12 week treatment of low energy diet plus exercise. Another group of five women lost 4.4 ± 0.7 kg FM with a 12 week treatment of an adequate diet plus exercise. Within each treatment, the amount of FM lost varied by approximately 2-fold. To explain the variability in FM loss, we tested its association by multiple regression analysis with several physiological and biochemical measurements obtained during a 2 week stabilization period or early in the treatment period. The variable most closely correlated with FM loss was plasma free fatty acid levels following exercise (EX-FFA). This variable alone accounted for 79 percent of the variation in FM loss. EX-FFA was simple to measure and was repeatedly correlated with FM loss, whether FFA values of the first exercise test or EX-FFA values obtained later in the experimental period were used. Of the physiological variables tested, the rate of fat calories expended in response to a test meal was correlated with FM loss and accounted for 71 percent of the variation. Upon subsequent testing, however, this relationship was not repeatable. When a treatment group designation (dummy-coded variable) was added to the regression analysis, the rate of fat calories expended at rest (FAT(RMR)) was related to FM loss. Together, FAT(RMR) and the dummy-coded variable accounted for 87 percent of the variation in FM loss. In a separate multiple regression equation, the combination of EX-FFA and the dummy-coded variable also accounted for 87 percent of the variation in FM loss. Further evaluation of these relationships is required to determine if EX-FFA or FAT(RMR) would be useful as predictors of FM loss under conditions of weight loss where individuals are living freely in the community and consuming a variety of diets.

Original languageEnglish (US)
Pages (from-to)283-293
Number of pages11
JournalInternational Journal of Obesity
Issue number4
StatePublished - 1991
Externally publishedYes



  • Fat utilization
  • Free fatty acids
  • Lipolysis
  • Resting metabolic rate
  • Weight reduction

ASJC Scopus subject areas

  • Food Science
  • Endocrinology
  • Medicine (miscellaneous)
  • Endocrinology, Diabetes and Metabolism
  • Public Health, Environmental and Occupational Health

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