Proceedings of The Physiological Society

AstraZeneca (2010) Proc Physiol Soc 18, PC29

Poster Communications

The association of body mass index with gastric emptying and effect of an exercise intervention on gastric emptying and appetite in adolescent girls

K. Horner1, D. Harrington1, A. E. Donnelly1, A. Shafat1

1. Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.

Gastric emptying (GE) plays a role in appetite regulation and has been implicated in the pathogenesis of obesity. Regular exercise may be one factor which moderates GE. We investigated (i) the relationship between GE and body mass index (BMI) and (ii) the effects of an exercise intervention on GE, appetite and food intake in adolescent girls. Nineteen healthy adolescent females (BMI 22.1±2.1 kg m-2; age 16.3±0.3 years) attended the laboratory, after giving written informed consent, on 2 occasions, at week 0 and week 8. Subjects were selected as those participating in no other physical activity classes or sport outside of physical education classes and were randomly assigned to exercise or control groups. GE was assessed by 13C octanoic acid breath test, subjective appetite sensations by 100mm visual analogue scales and food intake at a buffet meal. During weeks 1 to 7 subjects attended three classes per week of either a moderate intensity exercise class (exercise group; (EXE): n = 9) or a non-exercise class (control group (CTL); n = 10). Statistical analysis was conducted using Pearson correlations, independent t-test and Mixed ANOVA (group x time). Increasing BMI was significantly associated with increases in GE lag (r = 0.68, p = 0.001), latency (r = 0.62, p = 0.005) and half times (r = 0.62, p = 0.005) all indicating slower gastric emptying. Exercise intervention did not significantly alter GE or food intake compared to the CTL group. GE half time significantly increased in both EXE and CTL over time (main effect, p = 0.043). Hunger ratings at 30min after the standardised test meal were reduced in the EXE group over time (-13.4 ± 17.9mm) compared to a mean increase (4.8 ± 16.2mm) in the CTL group (p = 0.032). Interestingly, others have reported increases in glucagon-like peptide 1 at this time point following exercise intervention. Findings indicate increasing BMI is associated with slower GE in adolescent girls. The 7 week exercise intervention reduced 30 min postprandial hunger ratings but did not significantly influence GE compared to a control group.

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