title: A Human Thrifty Phenotype Associated With Less Weight Loss During Caloric Restriction.
abstract: Successful weight loss is variable for reasons not fully elucidated. Whether effective weight loss results from smaller reductions in energy expenditure during caloric restriction is not known. We analyzed whether obese individuals with a "thrifty" phenotype, that is, greater reductions in 24-h energy expenditure during fasting and smaller increases with overfeeding, lose less weight during caloric restriction than those with a "spendthrift" phenotype. During a weight-maintaining period, 24-h energy expenditure responses to fasting and 200% overfeeding were measured in a whole-room indirect calorimeter. Volunteers then underwent 6 weeks of 50% caloric restriction. We calculated the daily energy deficit (kilocalories per day) during caloric restriction, incorporating energy intake and waste, energy expenditure, and daily activity. We found that a smaller reduction in 24-h energy expenditure during fasting and a larger response to overfeeding predicted more weight loss over 6 weeks, even after accounting for age, sex, race, and baseline weight, as well as a greater rate of energy deficit accumulation. The success of dietary weight loss efforts is influenced by the energy expenditure response to caloric restriction. Greater decreases in energy expenditure during caloric restriction predict less weight loss, indicating the presence of thrifty and spendthrift phenotypes in obese humans.
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ martin.reinhardt@nih.gov.
authors.forename: Martin
authors.initials: M
authors.lastname: Reinhardt
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ.
authors.forename: Marie S
authors.initials: MS
authors.lastname: Thearle
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Ibrahim
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ.
authors.forename: Maximilian G
authors.initials: MG
authors.lastname: Hohenadel
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ.
authors.forename: Clifton
authors.initials: C
authors.lastname: Bogardus
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Krakoff
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, AZ.
authors.forename: Susanne B
authors.initials: SB
authors.lastname: Votruba
mesh_terms: D000328:Adult; D001481:Basal Metabolism / Q000235:genetics; D001823:Body Composition / Q000235:genetics; D015992:Body Mass Index; D001835:Body Weight / Q000235:genetics*; D031204:Caloric Restriction; D002153:Calorimetry, Indirect; D002149:Energy Intake; D004734:Energy Metabolism / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000178:diet therapy* / Q000235:genetics; D010641:Phenotype; D015431:Weight Loss / Q000235:genetics*; D055815:Young Adult