title: Investigation into the acute effects of total and partial energy restriction on postprandial metabolism among overweight/obese participants.
abstract: The intermittent energy restriction (IER) approach to weight loss involves short periods of substantial (75-100 %) energy restriction (ER) interspersed with normal eating. This study aimed to characterise the early metabolic response to these varying degrees of ER, which occurs acutely and prior to weight loss. Ten (three female) healthy, overweight/obese participants (36 (SEM 5) years; 29·0 (sem 1·1) kg/m2) took part in this acute three-way cross-over study. Participants completed three 1-d dietary interventions in a randomised order with a 1-week washout period: isoenergetic intake, partial 75 % ER and total 100 % ER. Fasting and postprandial (6-h) metabolic responses to a liquid test meal were assessed the following morning via serial blood sampling and indirect calorimetry. Food intake was also recorded for two subsequent days of ad libitum intake. Relative to the isoenergetic control, postprandial glucose responses were increased following total ER (+142 %; P=0·015) and to a lesser extent after partial ER (+76 %; P=0·051). There was also a delay in the glucose time to peak after total ER only (P=0·024). Both total and partial ER interventions produced comparable reductions in postprandial TAG responses (-75 and -59 %, respectively; both P<0·05) and 3-d energy intake deficits of approximately 30 % (both P=0·015). Resting and meal-induced thermogenesis were not significantly affected by either ER intervention. In conclusion, our data demonstrate the ability of substantial ER to acutely alter postprandial glucose-lipid metabolism (with partial ER producing the more favourable overall response), as well as incomplete energy-intake compensation amongst overweight/obese participants. Further investigations are required to establish how metabolism adapts over time to the repeated perturbations experienced during IER, as well as the implications for long-term health.
authors.affiliation: 1Nutrition, Metabolism and Diabetes Research Group, Faculty of Health and Medical Sciences,University of Surrey,Guildford GU2 7WG,UK.
authors.forename: Rona
authors.initials: R
authors.lastname: Antoni
authors.affiliation: 2Lighterlife UK Ltd,Cavendish House,Parkway,Harlow Business Park,Essex CM19 5QF,UK.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Johnston
authors.affiliation: 1Nutrition, Metabolism and Diabetes Research Group, Faculty of Health and Medical Sciences,University of Surrey,Guildford GU2 7WG,UK.
authors.forename: Adam L
authors.initials: AL
authors.lastname: Collins
authors.affiliation: 1Nutrition, Metabolism and Diabetes Research Group, Faculty of Health and Medical Sciences,University of Surrey,Guildford GU2 7WG,UK.
authors.forename: M Denise
authors.initials: MD
authors.lastname: Robertson
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D031204:Caloric Restriction / Q000009:adverse effects*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D018592:Cross-Over Studies; D050528:Diet, Carbohydrate-Restricted / Q000009:adverse effects*; D004038:Diet, Reducing / Q000009:adverse effects*; D002149:Energy Intake; D004739:England / Q000453:epidemiology; D005215:Fasting / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy* / Q000378:metabolism / Q000503:physiopathology; D050177:Overweight / Q000097:blood / Q000178:diet therapy* / Q000378:metabolism / Q000503:physiopathology; D019518:Postprandial Period; D012306:Risk; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D014280:Triglycerides
keywords: 3-OHB 3-β-hydroxybutyrate; Alternate-day fasting; CVD; Cardiometabolic risk; ER energy restriction; IER intermittent energy restriction; Intermittent energy restriction; Intermittent fasting; REE resting energy expenditure; Type 2 diabetes; dAUC decremental AUC; iAUC incremental AUC