Now showing 1 - 4 of 4
  • Publication
    Effects of a casein hydrolysate versus intact casein on gastric emptying and amino acid responses
    Purpose Milk proteins and/or their hydrolysates have been reported to have beneficial effects for improving postprandial glycaemia. Gastric emptying is a major determinant of postprandial glycaemia, yet limited studies have examined the effects of intact milk proteins compared to hydrolysates on gastric emptying. We investigated gastric emptying of a casein hydrolysate compared to intact casein. Methods Nine overweight and obese adults (mean ± SD age: 59.5 ± 6.5 years and BMI 28.4 ± 2.6 kg/m2) were studied in a randomised crossover design. Gastric emptying was assessed by paracetamol absorption test, with HPLC-MS being used for determining paracetamol and its primary metabolites in plasma. Glucose, insulin and amino acid responses were also assessed. Results Linear mixed model analysis showed no effect of treatment [F(1, 55) = 2.1, P = 0.16] or treatment × time interactions [F(6, 54) = 1.5, P = 0.21] for paracetamol concentrations. In addition, there were no significant differences between the intact casein and hydrolysate for any of the gastric emptying outcome measures (Cmax, AUC0–30min, AUC0–60min; AUC0–240min). However, insulin was increased in the early postprandial period (iAUC0–15min, iAUC0–30min; P < 0.05) and there was a treatment effect for glucose [F(1, 53) = 5.3, P = 0.03] following the casein hydrolysate compared to intact casein. No significant differences in amino acids were found between the two conditions. Conclusions Gastric emptying of a casein hydrolysate compared to intact casein does not differ. Mechanisms other than gastric emptying, for example the presence of a bioactive peptide sequence, may contribute to the glycaemic management effects of certain milk protein hydrolysates and warrant further investigation.
      291Scopus© Citations 6
  • Publication
    Sweet and umami taste perception differs with habitual exercise in males
    Taste is influenced by several factors. However, whether habitual exercise level is associated with differences in taste perception has received little investigation. The aim of this study was to determine if habitual exercise is associated with differences in taste perception in men. Active (n = 16) and inactive (n = 14) males, between ages 18–55, underwent two days of sensory testing, using prototypical taste stimuli of high and low concentrations for sweet, salt, bitter, sour, umami, and carbohydrate (maltodextrin). Mean perceived intensity and hedonic ratings were recorded. Eating behaviour was assessed by the three factor eating questionnaire and food intake by EPIC food frequency questionnaire (FFQ). There were moderate to large differences between the two groups in perceived intensity for sweet taste at the high concentration and umami taste at both high and low concentrations, with active males recording a higher perceived intensity (p < 0.05 for all). The active group also recorded a greater dislike for umami low and carbohydrate low concentration (p < 0.01). Salt, bitter and sour perception did not significantly differ between the two groups. FFQ analysis showed no difference in % energy from macronutrients between the groups. Eating behaviour traits correlated with sweet taste intensity and umami taste liking, independent of activity status. Results indicated that sweet and umami taste perception differ in active compared to inactive males. Habitual exercise level should be considered in taste perception research and in product development. Whether differences in taste perception could be one factor influencing food intake and thus energy balance with habitual exercise warrants further investigation.
      263Scopus© Citations 17
  • Publication
    Food reward in active compared to inactive men: Roles for gastric emptying and body fat
    Habitual exercise could contribute to weight management by altering processes of food reward via the gut-brain axis. We investigated hedonic processes of food reward in active and inactive men and characterised relationships with gastric emptying and body fat. Forty-four men (active: n = 22; inactive: n = 22, BMI range 21-36 kg/m2; percent fat mass range 9-42%) were studied. Participants were provided with a standardised fixed breakfast and an ad libitum lunch meal 5 h later. Explicit liking, implicit wanting and preference among high-fat, low-fat, sweet and savoury food items were assessed immediately post-breakfast (fed state) and again pre-lunch (hungry state) using the Leeds Food Preference Questionnaire. Gastric emptying was assessed by 13C-octanoic acid breath test. Active individuals exhibited a lower liking for foods overall and a greater implicit wanting for low-fat savoury foods in the fed state, compared to inactive men. Differences in the fed state remained significant after adjusting for percent fat mass. Active men also had a greater increase in liking for savoury foods in the interval between breakfast and lunch. Faster gastric emptying was associated with liking for savoury foods and with an increase in liking for savoury foods in the postprandial interval. In contrast, greater implicit wanting for high-fat foods was associated with slower gastric emptying. These associations were independent of each other, activity status and body fat. In conclusion, active and inactive men differ in processes of food reward. The rate of gastric emptying may play a role in the association between physical activity status and food reward, via the gut-brain axis.
      377Scopus© Citations 15
  • Publication
    Variable glycemic responses to intact and hydrolysed milk proteins in overweight and obese adults reveal the need for precision nutrition
    Background: Dietary modifications can contribute to improved pancreatic beta cell function and enhance glycemic control. Objective: The objectives of this study were to 1) investigate the potential of milk protein hydrolysates to modulate postprandial glucose response, 2) assess individual responses, 3) explore the inter and intra-individual reproducibility of the response. Methods: A 14-day randomized crossover study investigated interstitial glucose levels of participants in response to 12% w/v milk protein drinks (intact caseinate and casein hydrolysate A and B (CH-A and CH-B) consumed in random order with a 2-day washout between treatments. Milk protein drinks were consumed immediately prior to study breakfast and evening meals. Twenty participants (11 male/ 9 female) aged 50 ± 8 y with a body mass index of 30.2 ± 3.1 kg/m2 were recruited. Primary outcome was glucose levels assessed at 15 min intervals using glucose monitors. Results: Repeated measures-ANOVA revealed that for breakfast there was a significant difference across the three treatment groups (P = 0.037). The ability to reduce postprandial glucose was specific to CH-B in comparison to intact caseinate (P = 0.039). However, despite this significant difference further examination revealed that only three out of 18 individuals were classified as responders (P < 0.05). High intraclass correlation coefficients (ICCs) were obtained for glucose response to study meals (ICC: 0.892 for breakfast with intact caseinate). The inter-individual coefficient of variations (CVs) were higher than intra-individual CVs. Mean inter- and intra-individual CVs were 19.4% and 5.7%, respectively, for breakfast with intact caseinate. Conclusion: Ingestion of a specific casein hydrolysate successfully reduced the postprandial glucose response, however at an individual level only three participants were classified as responders, highlighting the need for precision nutrition. Exploration of high inter-individual responses to nutrition interventions is needed, in combination with the development of precision nutrition, potentially through an n-of-1 approach.
      107Scopus© Citations 5