title: A High Rate of Non-Compliance Confounds the Study of Whole Grains and Weight Maintenance in a Randomised Intervention Trial-The Case for Greater Use of Dietary Biomarkers in Nutrition Intervention Studies.
abstract: Observational studies consistently find an inverse relationship between whole-grain intake and weight gain. We aimed to confirm this in an open-label researcher-blinded parallel design randomised trial. A total of 179 overweight/obese women with a habitually low whole-grain intake (<16 g/day) were randomised to a weight maintenance diet with refined-grain (RG) or whole-grain (WG) foods (80 g/day) for 12 weeks after an initial weight loss program over 8 weeks. Body weight and composition was assessed at baseline, after the initial weight loss, and after the 12-week dietary intervention. During the 12-week dietary intervention phase, there were no group differences in changes in body weight and total fat mass %, whereas abdominal fat mass tended to increase more during the dietary intervention phase in the WG compared to the RG group (0.7 (SD 3.6) vs. -0.3 (SD 3.8) %;p= 0.052). Plasma alkylresorcinol concentrations, biomarkers of wholegrain wheat and rye intake, indicated poor compliance, particularly in the WG group, where >60% of participants had alkylresorcinol concentrations below 70 nmol/L, a concentration indicating low or no intake of whole-grain wheat. Further, weight regain was lower than expected in both intervention groups, further supporting a lack of compliance to the post-weight-loss diet. The rate of compliance was too low to conclude any effect of whole grain on weight maintenance, and reinforces the need to use objective measures of compliance in nutrition intervention studies.
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen DK2200, Denmark. mekr@life.ku.dk.
authors.forename: Mette
authors.initials: M
authors.lastname: Kristensen
authors.affiliation: Optimed Clinical Research, Gieres 38610, France. xavier.pelletier@optimed.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Pelletier
authors.affiliation: Nestlé Research Center, Vers chez les Blanc, Lausanne 1800, Switzerland. alastair.ross@chalmers.se.|Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg 41296, Sweden. alastair.ross@chalmers.se.
authors.forename: Alastair B
authors.initials: AB
authors.lastname: Ross
authors.affiliation: Cereal Partners Worldwide, Orbe 1350, Switzerland. frank.b.thielecke@gmail.com.|T2 Goodness Ltd., Allschwil 4123, Switzerland. frank.b.thielecke@gmail.com.
authors.forename: Frank
authors.initials: F
authors.lastname: Thielecke
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D035843:Biomedical Research / Q000379:methods; D015992:Body Mass Index; D000068959:Body Weight Maintenance; D000072001:Diet, Healthy; D004038:Diet, Reducing; D005260:Female; D005602:France; D006801:Humans; D008875:Middle Aged; D052756:Nutritional Sciences / Q000379:methods; D000067329:Obesity, Metabolically Benign / Q000097:blood / Q000178:diet therapy / Q000517:prevention & control*; D050177:Overweight / Q000097:blood / Q000178:diet therapy / Q000517:prevention & control*; D010349:Patient Compliance; D017060:Patient Satisfaction; D012107:Research Design; D012118:Resorcinols / Q000097:blood; D055502:Secondary Prevention; D015431:Weight Loss; D000067348:Whole Grains; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012118:Resorcinols
keywords: alkylresorcinols; biomarkers; compliance; weight maintenance; whole grain