Prolonged chewing at lunch decreases later snack intake.
Appetite. 2013 Mar ;62:91-5. Epub 2012 Nov 30. PMID: 23207188
Suzanne Higgs, Alison Jones
Prolonged chewing of food can reduce meal intake. However, whether prolonged chewing influences intake at a subsequent eating occasion is unknown. We hypothesised that chewing each mouthful for 30s would reduce afternoon snack intake more than (a) an habitual chewing control condition, and (b) an habitual chewing condition with a pauses in between each mouthful to equate the meal durations. We further hypothesised that this effect may be related to effects of prolonged chewing on lunch memory. Forty three participants ate a fixed lunch of sandwiches in the laboratory. They were randomly allocated to one of the three experimental groups according to a between-subjects design. Appetite, mood and lunch enjoyment ratings were taken before and after lunch and before snacking. Snack intake of candies at a taste test 2h after lunch was measured as well as rated vividness of lunch memory. Participants in the prolonged chewing group ate significantly fewer candies than participants in the habitual chewing group. Snack intake by the pauses group did not differ from either the prolonged or habitual chewing groups. Participants in the prolonged chewing group were less happy and enjoyed their lunch significantly less than participants in other conditions. Appetite ratings were not different across groups. Rated vividness of lunch memory was negatively correlated with intake but there was no correlation with rated lunch enjoyment. Prolonged chewing of a meal can reduce later snack intake and further investigation of this technique for appetite control is warranted.
Article Published Date : Feb 28, 2013
Improvement in chewing activity reduces energy intake in one meal and modulates plasma gut hormone concentrations in obese and lean young Chinese men.
Am J Clin Nutr. 2011 Jul 20. Epub 2011 Jul 20. PMID: 21775556
Jie Li, Na Zhang, Lizhen Hu, Ze Li, Rui Li, Cong Li, Shuran Wang
Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, China.
BACKGROUND: As the first step in ingesting food, the effects of mastication on energy intake and gut hormones in both obese and lean subjects have not been extensively evaluated. OBJECTIVE: The current study aimed to compare the differences in chewing activities between obese and lean subjects and to examine the effects of chewing on energy intake and gut hormone concentrations in both obese and lean subjects. DESIGN: Sixteen lean and 14 obese young men participated in the current research. In study 1, we investigated whether the chewing factors of obese subjects were different from those of lean subjects. In study 2, we explored the effects of chewing on energy intake. A test meal consisting of 2200 kJ (68% of energy as carbohydrate, 21% of energy as fat, and 11% of energy as protein) was then consumed on 2 different sessions (15 chews and 40 chews per bite of a 10-g food) by each subject to assess the effects of chewing on plasma gut hormone concentrations. RESULTS: Compared with lean participants, obese participants had a higher ingestion rate and a lower number of chews per 1 g of food. However, obese participants had a bite size similar to that of lean subjects. Regardless of status, the subjects ingested 11.9% less after 40 chews than after 15 chews. Compared with 15 chews, 40 chews resulted in a lower energy intake and postprandial ghrelin concentration and higher postprandial glucagon-like peptide 1 and cholecystokinin concentrations in both lean and obese subjects. CONCLUSION: Interventions aimed at improving chewing activity could become a useful tool for combating obesity. This trial was registered at chictr.org as ChiCTR-OCC-10001181.
Article Published Date : Jul 20, 2011
Discovery of a novel and rich source of gluten-degrading microbial enzymes in the oral cavity.
PLoS One. 2010;5(10):e13264. Epub 2010 Oct 11. PMID: 20948997
Eva J Helmerhorst, Maram Zamakhchari, Detlef Schuppan, Frank G Oppenheim
BACKGROUND: Celiac disease is a T cell mediated-inflammatory enteropathy caused by the ingestion of gluten in genetically predisposed individuals carrying HLA-DQ2 or HLA-DQ8. The immunogenic gliadin epitopes, containing multiple glutamine and proline residues, are largely resistant to degradation by gastric and intestinal proteases. Salivary microorganisms however exhibit glutamine endoprotease activity, discovered towards glutamine- and proline-rich salivary proteins. The aim was to explore if gliadins can serve as substrates for oral microbial enzymes. METHODOLOGY/PRINCIPAL FINDINGS: Proteolytic activity in suspended dental plaque was studied towards a) gliadin-derived paranitroanilide(pNA)-linked synthetic enzyme substrates b) a mixture of natural gliadins and c) synthetic highly immunogenic gliadin peptides (33-mer ofα2-gliadin and 26-mer of γ-gliadin). In addition, gliadin zymography was conducted to obtain the approximate molecular weights and pH activity profiles of the gliadin-degrading oral enzymes and liquid iso-electric focusing was performed to establish overall enzyme iso-electric points. Plaque bacteria efficiently hydrolyzed Z-YPQ-pNA, Z-QQP-pNA, Z-PPF-pNA and Z-PFP-pNA, with Z-YPQ-pNA being most rapidly cleaved. Gliadin immunogenic domains were extensively degraded in the presence of oral bacteria. Gliadin zymography revealed that prominent enzymes exhibit molecular weights>70 kD and are active over a broad pH range from 3 to 10. Liquid iso-electric focusing indicated that most gliadin-degrading enzymes are acidic in nature with iso-electric points between 2.5 and 4.0. CONCLUSIONS/SIGNIFICANCE: This is the first reported evidence for gluten-degrading microorganisms associated with the upper gastro-intestinal tract. Such microorganisms may play a hitherto unappreciated role in the digestion of dietary gluten and thus protection from celiac disease in subjects at risk.
Article Published Date : Jan 01, 2010
[Study on lifestyle in patients with gastroesophageal reflux disease].
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2017 May 28;42(5):558-564
Authors: Yuan L, Tang D, Peng J, Qu N, Yue C, Wang F
OBJECTIVE: To investigate the correlation between certain unhealthy lifestyles and the incidence of gastroesophageal reflux disease (GERD), thus to provide the lifestyle guidelines for GERD patients. Methods: Retrospective study were conducted for 402 GERD and 276 non-GERD out-patients in Department of Gastroenterology, Third Xiangya Hospital, Central South University from August, 2014 to August, 2015 based on questionnaire survey, then the correlation of unhealthy lifestyles with GERD were analyzed. Results: The top 10 common symptoms for GERD were as follows: reflux, acid regurgitation, postprandial fullness, heartburn, swallow obstruction or pain, epigastric burning sensation, paraesthesia pharynges, poststernal pain, chronic laryngopharyngitis, and chronic cough. The top 8 unhealthy habits closely related to GERD were as follows: fast-eating, over-eating, spicy preferred diet, sweets preferred diet, anxious, soup preferred diet, high-fat diet, and hot eating. Single-factor analysis showed that GERD was markedly correlated to gender (male), age (≥60 years), BMI, smoking, alcohol, fast-eating, over-eating, hot-eating, spicy preferred diet, high-fat diet, acid preferred diet, sweets preferred diet, hard food preference, strong tea preference, coffee preference, immediately on bed after meal, difficult defecation, dyscoimesis, anxious, and too tight belt, respectively (P<0.05). Logistic multiple regression analysis indicated that the largest risk factor for GERD was the fast-eating (OR=3.214, 95% CI 2.171 to 4.759, P<0.001) followed by the over-eating (OR=2.936, 95% CI 1.981 to 4.350, P<0.001), elderly population (OR=2.047, 95% CI 1.291 to 3.244, P=0.002), too tight belt (OR=2.003, 95% CI 1.013 to 3.961, P=0.046), and hot-eating (OR=1.570, 95% CI 1.044 to 2.362, P=0.030). Conclusion: The elderly people are at high risk for GERD, and unhealthy habits like fast-eating, over-eating, too tight belt, and hot-eating is closely related to GERD. The lifestyles such as chewing food thoroughly, splitting the meals up, warm and cool diet, keeping patients out of the too tight belt are necessary for GERD patients.
PMID: 28626103 [PubMed - in process]