British Journal of Nutrition

Full Papers

Behaviour, Appetite and Obesity

The effect of intermittent energy and carbohydrate restriction v. daily energy restriction on weight loss and metabolic disease risk markers in overweight women

Michelle Harviea1 c1, Claire Wrighta2, Mary Pegingtona1, Debbie McMullana1, Ellen Mitchella1, Bronwen Martina3, Roy G. Cutlera4, Gareth Evansa1, Sigrid Whitesidea5, Stuart Maudsleya4, Simonetta Camandolaa3, Rui Wanga3, Olga D. Carlsona3, Josephine M. Egana3, Mark P. Mattsona4 and Anthony Howella1

a1 Genesis Breast Cancer Prevention Centre, University Hospital of South Manchester NHS Foundation Trust, Southmoor Road, Manchester M23 9LT, UK

a2 Department of Clinical Sciences and Nutrition, University of Chester, Cheshire, UK

a3 Laboratory of Clinical Investigation, National Institute on Aging Intramural Research Program, Baltimore, MD, USA

a4 Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA

a5 Department of Statistics, University Hospital of South Manchester NHS Foundation Trust, Southmoor Road, Manchester M23 9LT, UK

Abstract

Intermittent energy restriction may result in greater improvements in insulin sensitivity and weight control than daily energy restriction (DER). We tested two intermittent energy and carbohydrate restriction (IECR) regimens, including one which allowed ad libitum protein and fat (IECR+PF). Overweight women (n 115) aged 20 and 69 years with a family history of breast cancer were randomised to an overall 25 % energy restriction, either as an IECR (2500–2717 kJ/d, < 40 g carbohydrate/d for 2 d/week) or a 25 % DER (approximately 6000 kJ/d for 7 d/week) or an IECR+PF for a 3-month weight-loss period and 1 month of weight maintenance (IECR or IECR+PF for 1 d/week). Insulin resistance reduced with the IECR diets (mean − 0·34 (95 % CI − 0·66, − 0·02) units) and the IECR+PF diet (mean − 0·38 (95 % CI − 0·75, − 0·01) units). Reductions with the IECR diets were significantly greater compared with the DER diet (mean 0·2 (95 % CI − 0·19, 0·66) μU/unit, P= 0·02). Both IECR groups had greater reductions in body fat compared with the DER group (IECR: mean − 3·7 (95 % CI − 2·5, − 4·9) kg, P= 0·007; IECR+PF: mean − 3·7 (95 % CI − 2·8, − 4·7) kg, P= 0·019; DER: mean − 2·0 (95 % CI − 1·0, 3·0) kg). During the weight maintenance phase, 1 d of IECR or IECR+PF per week maintained the reductions in insulin resistance and weight. In the short term, IECR is superior to DER with respect to improved insulin sensitivity and body fat reduction. Longer-term studies into the safety and effectiveness of IECR diets are warranted.

(Received September 07 2012)

(Revised February 13 2013)

(Accepted February 13 2013)

(Online publication April 16 2013)

Key Words:

  • Intermittent energy restriction;
  • Low-carbohydrate diets;
  • Weight loss;
  • Daily energy restriction;
  • Insulin resistance

Correspondence

c1 Corresponding author: Dr M. Harvie, fax +44 161 291 4421, email michelle.harvie@manchester.ac.uk

Footnotes

  Abbreviations: DER, daily energy restriction; FFM, fat-free mass; HbA1c, glycated Hb; HOMA, homeostasis model assessment; IECR, intermittent energy and carbohydrate restriction; IECR+PF, intermittent energy and carbohydrate restriction+ad libitum protein and fat; IER, intermittent energy restriction; IGF-1, insulin-like growth factor 1; LOCF, last observation carried forward