title: Lean and obese dietary phenotypes: differences in energy and substrate metabolism and appetite.
abstract: This study aimed to characterise lean and obese phenotypes according to diet and body composition, and to compare fasting and postprandial appetite and metabolic profiles following a high-fat test meal. A total of ten lean (BMI40 and 30 kg/m2) high-fat consumers (OHF; >40 % energy from fat) were recruited. Before and following the test meal (4727 kJ (1130 kcal), 77 % fat, 20 % carbohydrate (CHO) and 3 % protein), fasting plasma glucose, insulin, leptin, ghrelin, peptide YY (PYY), RER, RMR and subjective appetite ratings (AR) were measured for 6 h. Thereafter, subjects consumed a self-selected portion of a standardised post-test meal (40 % fat, 45 % CHO and 15 % protein) and reported AR. Fasting (P=0·01) and postprandial (P<0·001) fat oxidation was significantly higher in LHF than in LLF but was not different between LHF and OHF. Although similar between the lean groups, fasting and postprandial energy expenditures were significantly higher in OHF compared with LHF (P<0·01). Despite similar AR across groups, LLF consumed a relatively greater quantity of the post-test meal than did LHF (7·87 (sd 2·96) v. 7·23 (sd 2·67) g/kg, P=0·013). The lean groups showed appropriate changes in plasma ghrelin and PYY following the test meal, whereas the OHF group showed a blunted response. In conclusion, the LHF phenotype had a greater capacity for fat oxidation, which may be protective against weight gain. OHF individuals had a blunted appetite hormone response to the high-fat test meal, which may subsequently increase energy intake, driving further weight gain.
authors.affiliation: 1Department of Human Biology,Division of Exercise Science and Sports Medicine, Faculty of Health Sciences,University of Cape Town,Cape Town 7725,South Africa.
authors.forename: Louise
authors.initials: L
authors.lastname: Clamp
authors.affiliation: 2Department of Human Biology,Division of Nutrition and Dietetics, Faculty of Health Sciences,University of Cape Town,Cape Town 7925,South Africa.
authors.forename: Anthony P J
authors.initials: AP
authors.lastname: Hehir
authors.affiliation: 1Department of Human Biology,Division of Exercise Science and Sports Medicine, Faculty of Health Sciences,University of Cape Town,Cape Town 7725,South Africa.
authors.forename: Estelle V
authors.initials: EV
authors.lastname: Lambert
authors.affiliation: 3Division of Gastroenterology,University Hospital,4031 Basel,Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Beglinger
authors.affiliation: 4Non-communicable Disease Research Unit,South African Medical Research Council,Tygerberg 7505,South Africa.
authors.forename: Julia H
authors.initials: JH
authors.lastname: Goedecke
mesh_terms: D000328:Adult; D001066:Appetite / Q000502:physiology*; D001481:Basal Metabolism; D001823:Body Composition; D015992:Body Mass Index; D004032:Diet; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000378:metabolism; D002149:Energy Intake; D005215:Fasting; D005260:Female; D054439:Ghrelin / Q000097:blood; D006801:Humans; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology*; D010084:Oxidation-Reduction; D019894:Peptide YY / Q000097:blood; D010641:Phenotype; D019518:Postprandial Period; D012527:Satiation / Q000502:physiology; D011795:Surveys and Questionnaires; D013851:Thinness / Q000378:metabolism*; D015430:Weight Gain / Q000502:physiology
chemical_list: D004041:Dietary Fats; D054439:Ghrelin; D019894:Peptide YY
keywords: AR appetite ratings; CHO carbohydrate; Diet; FFM fat-free mass; Fat oxidation; Ghrelin; LHF lean high-fat; LLF lean low-fat; OHF obese high-fat; PYY peptide YY; Peptide YY; RER; RMR; SFQ Short Fat Questionnaire; TE total energy; TFEQ Three Factor Eating Questionnaire