The Sum of lts Parts-Effects of Gastric Distention, Nutrient Content and Sensory Stimulation on Brain Activation
Spetter, M.S. ; Graaf, C. de; Mars, M. ; Viergever, M.A. ; Smeets, P.A.M. - \ 2014
PLoS ONE 9 (2014)3. - ISSN 1932-6203 - 10 p.
body-weight regulation - food-intake - feeding-behavior - eating behavior - human amygdala - appetite - humans - satiety - taste - fat
During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to assess the effect of gastric distention with an intra-gastric load and the additional effect of oral stimulation on brain activity after food administration. Our secondary objective was to study the correlations between hormone responses and appetite-related ratings and brain activation. Fourteen men completed three functional magnetic resonance imaging sessions during which they either received a naso-gastric infusion of water (stomach distention), naso-gastric infusion of chocolate milk (stomach distention + nutrients), or ingested chocolate-milk (stomach distention + nutrients + oral exposure). Appetite ratings and blood parameters were measured at several time points. During gastric infusion, brain activation was observed in the midbrain, amygdala, hypothalamus, and hippocampus for both chocolate milk and water, i.e., irrespective of nutrient content. The thalamus, amygdala, putamen and precuneus were activated more after ingestion than after gastric infusion of chocolate milk, whereas infusion evoked greater activation in the hippocampus and anterior cingulate. Moreover, areas involved in gustation and reward were activated more after oral stimulation. Only insulin responses following naso-gastric infusion of chocolate milk correlated with brain activation, namely in the putamen and insula. In conclusion, we show that normal (oral) food ingestion evokes greater activation than gastric infusion in stomach distention and food intake-related brain areas. This provides neural evidence for the importance of sensory stimulation in the process of satiation.
Cephalic phase responses and appetite
Smeets, P.A.M. ; Erkner, A. ; Graaf, C. de - \ 2010
Nutrition Reviews 68 (2010)11. - ISSN 0029-6643 - p. 643 - 655.
sensory-specific satiety - plasma ghrelin levels - pancreatic-polypeptide release - body-weight regulation - food-intake - sweet taste - insulin-secretion - nutritional implications - vagal-stimulation - glucose-tolerance
The current food supply in many parts of the world differs substantially from that which existed during most of human evolution. It is characterized by a high variety of palatable foods with high energy density and low fiber content. Many foods can be eaten very quickly, and there is not always congruency between the sensory properties of the food and the subsequent metabolic consequences of its ingestion, (e.g., as in the consumption of artificially sweetened foods). It is not presently known how the human body copes with this incongruent food environment in terms of short-term satiety responses and long(er)-term regulation of food intake. Cephalic phase responses (CPRs) are innate and learned physiological responses to sensory signals that prepare the gastrointestinal tract for the optimal processing of ingested foods. CPRs could be affected by inconsistencies in the associations between sensory signals and subsequent post-ingestive consequences. Reviewed here are the available data on how CPRs affect the control of food intake