Satiation, Satiety Clinical Trial
Official title:
Experimental Study to Investigate the Effect of a High Fibre, Polydextrose-enriched Tomato Soup on Food Intake, the Experience of Appetite and Biomarkers of Satiation and Satiety
This study will examine the impact of a soluble fibre (polydextrose) incorporated into a high fibre tomato soup on food intake (amount and choice), appetite ratings and biomarkers of satiation and satiety over 4-weeks. Specifically, the impact on the development of satiation within the fixed-load tomato soup containing the fibre, the development of satiety after the fixed-load meal containing fibre and intake at subsequent ad libitum meals will be examined as well as the insulin response and carbohydrate fermentation before and after 4-week dosing of the preload soup.
The science underpinning both short (episodic) and long (tonic) term appetite regulation
demonstrates that foods higher in macronutrients such as fibre can, under certain
experimental conditions, produce great decreases in feelings of hunger and increases in
fullness, post consumption, compared to equi-caloric loads of high carbohydrate or high fat.
Given that fibre increases the release of GLP-1, slows down gastric emptying, prolongs
nutrient absorption and, over long-term use increases the generation of short chain fatty
acids (SCFAs) which have been linked to improved satiety responding, it is plausible that it
will produce strong effects on within meal processes of satiation and satiety over the
short- and long-term. Fibre has also been suggested to influence carbohydrate fermentation
(via generation of these SCFAs) and improve the insulin response, additionally improving
satiety. Ingredients may be added to boost fibre content such as the use of polydextrose,
which is a non-digestible polysaccharide usually used as a dietary fibre in foods.
Polydextrose has also been shown to increase levels of SCFAs due to its slow fermentation
and has been related to reductions in subsequent intake and/or reduced hunger.
The aim of the current study is to assess the impact of a high fibre, polydextrose enriched
tomato soup (experimental) or a low fibre tomato soup (control) on food intake, the
experience of appetite and biomarkers of satiation and satiety.
Sample size: 86 males aged between 18 and 55 years with a body mass index (BMI) of between
23.0 and 28.0 kg/m2. A subset of 28 participants will undergo additional finger prick blood
glucose and hydrogen breath test measures to assess biomarkers of satiation and satiety.
Power calculations to ensure sufficient participants are included were based on power
expected for a medium effect (0.25) at 80% power for a 2 condition between-measures design
using G*power.
Methods: Participants will be invited to three full test day (baseline control, session 1;
first dosing, session 2; one day prior to final dosing, session 3) sessions in which they
will be provided with breakfast (tailored to individual resting metabolic rate (RMR) using
the Schofield equation), the preload condition (receiving a high fibre polydextrose enriched
or control tomato soup) one hour before an ad-libitum lunch and followed four hours later by
an ad-libitum dinner and snack box. All test days will involve the use of standard operating
proceedures. Pre-packaged portions of soup will be provided for a 4-week dosing period
between study sessions 2 and 3 for all participants.
A subset of participants (N=28) will additionally undergo 3 further testing sessions
(baseline control, session 0; second dosing, session 3; final dosing, session 4) in which a
breakfast will be provided followed by the test product with additional glucose and
carbohydrate fermentation measures collected for 3 hours before a light fixed portion meal.
Throughout test days participants will complete visual analogue scales (VAS) for appetite
and palatability as well as questionnaires pertaining to eating behaviour and current
sensations (including a gastrointestinal distress questionnaire).
Statistical analysis: Primary analysis will be comparison of subsequent ad-libitum energy
intake between high fibre polydextrose enriched tomato soup compared to control using ANOVA
and post-hoc tests. Meal duration and various appetite ratings will also be analysed as will
biomarkers of satiety. The specified participant numbers (n=86) give an 80% probability of
detecting an effect on energy intake.
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Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science