Effect of Oligofructose on Appetite in Overweight Subjects

Not Applicable

Completed

Conditions: Appetite Regulation
Obesity

Interventions: Dietary Supplement: Oligofructose
Dietary Supplement: Placebo

Registration Number: NCT00912197

Lead Sponsor: Imperial College London

Brief Summary: This study seeks to look into the effects of oligofructose supplementation on appetite, energy intake, and body weight and body composition in overweight subjects. Compared to a placebo product (cellulose) oligofructose is hypothesised to suppress hunger and thereby reduce food intake moderately leading to a decrease in body weight.

Detailed Description: Appetite regulation plays an important part in energy balance. Suppressing appetite by manipulating the diet is a safe way of reducing energy intake and body weight compared to drug therapy and obesity surgery. How various nutrients affect appetite is not fully understood. Non-digestible carbohydrates (NDC) may affect appetite differently due to differences in physio-chemical properties.

This project will look into how two different NDC affect appetite and energy intake in overweight individuals in a randomised, double-blinded, placebo controlled parallel study. The NDC under investigation are oligofructose and cellulose, both natural compounds of plant origin. The former is broken down (fermented) in the large bowel by friendly bacteria producing various compounds that may affect appetite and the metabolism of the host.

Volunteers will consume one of the two NDC for eight weeks (including a two week run-in period). Appetite study session, functional MRI (fMRI) and MRI body fat scans will be conducted before and after the supplementation with NDC (or during the supplementation in the case of fMRI). Using fMRI the effect of the NDC supplementation on central appetite regulating centres will be investigated. Appetite questionnaires and dietary records will completed under free-living conditions at baseline and during the supplementation to explore the effect on subjective appetite feelings and energy intake, respectively.

It is hoped that this project will enhance the understanding of how NDC affect appetite and provide further information on how fermentation of NDC, gut hormone release, body composition, and appetite regulation are linked.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 28

Inclusion Criteria

Healthy males and females aged 20-50
BMI 25-35 kg/m2
Weight stable for three months prior to enrollment in study (weight change < 3 kg over a period of three months)
Habitual dietary fibre ≤ 25g/day (as assessed by 3-day dietary record)
Non-smokers
No current or history of endocrine disease, gastrointestinal disease, kidney or liver diseases, cardiovascular disease, pancreatitis, or cancer
Hydrogen producers

Exclusion Criteria

Use of antibiotic less than three months prior to participation in the study
Participation in other research studies in the previous three months
Blood donation less than three months before participation in study
Anaemia
Hypertension
Pregnancy or breastfeeding
Substance abuse
Vegan diet
Regular use of prebiotic, probiotic or symbiotic food items/ supplements
Intense exercise undertaken for more than 5h per week
Metallic or electronic implants e.g. pacemaker, cochlear ear implants, fixed dental braces
Claustrophobia
Depression

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Oligofructose	Oligofructose	Participants received 10g of Oligofructose powdered supplements in sachets each containing 10 g dietary fiber) three times per day. Volunteers were instructed to take the supplement with their main meals.The 8-week supplementation period took place between visits 3 and 4 and included a 2-week run-in period to allow the bowel to adapt to the 30 g of dietary fiber.
Cellulose and maltodextrin	Placebo	Participants received 10g of Cellulose powdered supplements in sachets each containing 10 g dietary fiber) three times per day. Volunteers were instructed to take the supplement with their main meals. Maltodextrin was added to the cellulose supplement. The 8-week supplementation period took place between visits 3 and 4 and included a 2-week run-in period to allow the bowel to adapt to the 30 g of dietary fiber.

Primary Outcome Measures

Name	Time	Method
Gut Hormone PYY	baseline (Day 0) and post-supplementation (Day 56)	Total PYY concentrations were quantified using specific and sensitive in-house radio-immunoassays as previously described.
Subjective Appetite Ratings in Fullness Compared to Baseline	Baseline, 56 days	Fullness are assessed by visual analogue scale, 10 cm in length with words anchored at each end, expressing the most positive (feel full: maximum Score=10cm) and the most negative rating (feeling empty: Minimum Score = 0cm), values at baseline and after treatments at 56 days
Body Weight	Baseline, 56 days
Subjective Appetite Ratings in Hunger Compared to Baseline	Baseline, 56 days	Hunger was assessed by visual analogue scales (Each scale is 10cm in length with words anchored at each end, expressing the most positive (Minimum score = 0 cm and means no hunger) and the most negative rating (Maximum score = 10 cm and means very hungry). Compared to baseline after treatment at 56 days
Energy Intake	Baseline, 56 days	Energy intake was assessed by 7-days food diary at baseline and last week of treatment, diaries were analysed by Dietplan6 software. The values in the table represent the Energy intake as measured over the whole week (as opposed to reporting the Energy intake per day based on the 7 day data).

Secondary Outcome Measures

Name	Time	Method
Serum Insulin	baseline (Day 0) and post-supplementation (Day 56)	Plasma insulin concentrations were assayed using RIA kits (Millipore, MO).
Glycemic Response	baseline (Day 0) and post-supplementation (Day 56)	Glucose was analyzed in the Department of Clinical Biochemistry, Hammer-smith Hospital, London using an Abbott Architect ci8200 analyzer(Abbott Diagnostics, Maidenhead, UK).
Breath Hydrogen Levels	baseline (Day 0) and post-supplementation (Day 56)	breath hydrogen were obtained from volunteers throughout the study session.
Plasma Short-chain Fatty Acids Concentrations After Treatment	Baseline, 56 days	Short-chain fatty acids (acetate, propionate, butyrate) concentrations assessed from plasma at 56 days at 450min timepoint with gas chromatography
Imaging of Total Adipose Tissue	Baseline, 56 days	Total adipose tissue was assessed by FMRI at baseline and after treatment period
Inflammatory Markers	baseline (Day 0) and post-supplementation (Day 56)	No data were collected for this Outcome Measure
Body Composition	Baseline, 56 days	Body composition assessed by BMI