Year: 2012
Type: dissertation
Abstract: In the current situation where obesity has reached pandemic proportions, it is important to understand dietary factors that affect appetite and food intake both in short-and long-term.Besides the dietary composition the structure and physical form of food play an important role in the regulation of appetite and food intake.The synergetic effects of food properties modulate the postprandial systemic functions and affect ultimately energy balance.Gut-brain cross-talk, the core of appetite control, coordinates short-and long-term signals that serve energy balance.In this process the neuroendocrine system in the gastrointestinal (GI) tract plays a major role by adjusting digestion through the release of several peptide hormones in response to energy status and various food-related stimuli.The intrinsic characteristics of dietary components are known to modulate postprandial physiology including GI peptide release which in turn modulates GI functions and metabolism.The aim of this work was to investigate the postprandial effects of dietary fibres and proteins and their structural modification on postprandial appetite and appetite-related GI responses in healthy normal-weight individuals.Psyllium fibre enrichment of vegetable patties suppressed postprandial metabolic and GI peptide responses.The effects of simultaneous soy protein enrichment were less evident.Oat bran enrichment of the semisolid porridge lowered glucose and insulin responses, whereas GI peptide responses were comparable among oat and wheat bran containing products.Oat bran-enriched beverage with lowered viscosity stimulated postprandial metabolic and GI peptide responses, accelerated gastric emptying and increased satiety, which was not the case when viscosity of the oat bran beta-glucan was maintained.Caseinate and whey protein produced different, protein-specific postprandial amino acid profile and cholecystokinin response.Enzymatically crosslinked caseinate consumed in beverage form did not affect postprandial responses, whereas crosslinked caseinate in gel form suppressed metabolic and GI peptide responses and increased fullness.In conclusion, viscous dietary fibre both in solid and liquid food matrix and the physical form of food modifies gastric emptying, GI peptide responses and appetite ratings.These data emphasize the importance of dietary fibre and food form in modifying the short-term physiological and appetite responses.
Author: Kristiina Juvonen
Language: English
Subfield: Endocrine and Autonomic Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
Funders: Itä-Suomen Yliopisto, Oulun Yliopisto
OpenAlex ID: W3097574168