Full Papers

Effect of two doses of a mixture of soluble fibres on body weight and metabolic variables in overweight or obese patients: a randomised trial

Jordi Salas-Salvadó^a1 c1, Xavier Farrés^a2, Xavier Luque^a3, Silvia Narejos^a4, Manel Borrell^a5, Josep Basora^a6, Anna Anguera^a7, Ferran Torres^a8, Mònica Bulló^a1, Rafel Balanza^a1 and for the Fiber in Obesity-Study Group†

^a1 Human Nutrition Unit, Facultat de Medicina i Ciències de la Salut, Hospital Universitari de Sant Joan, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain

^a2 Centre d'Atenció Primària el Remei de Vic, Servei Català de la Salut, Barcelona, Spain

^a3 Centre d'Atenció Primària d'Alcover, Servei Català de la Salut, Barcelona, Spain

^a4 Centre d'Atenció Primària de Centelles, Servei Català de la Salut, Barcelona, Spain

^a5 Centre d'Atenció Primària Sarrià, Servei Català de la Salut, Barcelona, Spain

^a6 Centre d'Atenció Primària Reus I, Institut Català de la Salut, Reus, Spain

^a7 Research Department, Madaus, S.A., Barcelona, Spain

^a8 Laboratorio de Bioestadística y Epidemiologia, Servei de Farmacología Clínica, Hospital Clínic, Universitat Autònoma de Barcelona, Barcelona, Spain

Abstract

The aim of the study was to compare the effect of the administration of a mixture of fibres on body weight-loss, satiety, lipid profile and glucose metabolism. We included 200 overweight or obese patients in a parallel, double-blind, placebo-controlled clinical trial, who were randomised to receive, in the context of an energy-restricted diet for a period of 16 weeks, a mixed fibre dose (3 g Plantago ovata husk and 1 g glucomannan) twice (b.i.d. group) or three times daily (t.i.d. group) or placebo. Weight change was the primary efficacy endpoint. Satiety, dietary compliance, lipid profile, glucose tolerance, insulin resistance and high-sensitivity C-reactive protein were secondary endpoints. Weight loss tended to be higher after both doses of fibre ( − 4·52 (sd 0·56) and − 4·60 (sd 0·55) kg) than placebo ( − 0·79 (sd 0·58) kg); the differences in changes between groups were not statistically significant. Postprandial satiety increased in both fibre groups compared to the placebo. The differences between groups in LDL-cholesterol levels were significant (P = 0·03), with greater reductions in the two fibre-supplemented groups ( − 0·38 (sd 0·10) and − 0·24 (sd 0·09) mmol/l in the b.i.d. and t.i.d. groups v. − 0·06 (sd 0·09) mmol/l in placebo group). A similar pattern was observed for changes in total cholesterol:HDL-cholesterol and HDL-cholesterol:LDL-cholesterol ratios. Interventions were well tolerated and had no effects on HDL-cholesterol, glucose and insulin concentrations, glucose tolerance or high-sensitivity C-reactive protein. In conclusion, a 16-week dietary supplement of soluble fibre in overweight or obese patients was well tolerated, induced satiety and had beneficial effects on some CVD risk factors, the most important of which was a significant decrease in plasma LDL-cholesterol concentrations.

(Received May 28 2007)

(Revised October 23 2007)

(Accepted October 25 2007)

(Online publication November 22 2007)

Key Words:

• Dietary fibre;
• Glucomannan;
• Plantago;
• Body weight;
• Lipid profile

Correspondence:

^c1 Corresponding author: Dr J. Salas-Salvadó, fax +34 977 75 93 22, email jordi.salas@urv.cat

Footnotes

†  The investigators participating in the Fiber in Obesity-Study Group are listed in the Acknowledgements.

Abbreviations: b.i.d., experimental treatment with mixed fibre dose given twice daily; t.i.d., experimental treatment with mixed fibre dose given three times daily; HOMA-IR, homeostasis model assessment of insulin resistance; ITT, intention-to-treat; OGTT, oral glucose tolerance test