Three studies were designed to investigate the hypothesis that physiological and environmental variables are both independent and interactive in determining food intake (FI) in children and adolescents during puberty (8 – 18 y old). Study 1 investigated the effect of obesity, sex and pubertal status on appetite hormones in response to a mixed glucose and whey protein (WP) drink in adolescents. Obese adolescents had higher insulin, PYY and lower ghrelin than normal weight (NW) controls, with a more pronounced effect in males. Puberty did not affect insulin, but the change in PYY in response to the drink was greater and ghrelin was lower in mid-late pubertal than pre-early pubertal obese males. To further describe the role of puberty, Study 2 examined the effect of pubertal status on FI following consumption of glucose and WP drinks in male and female children. In mid-late pubertal children, mealtime compensation for energy from glucose was less at 60 than at 30 min, but not for whey. However, compensation for either drink was not different at 30 and 60 min meals in pre-early pubertal children. Finally to demonstrate the interaction between puberty and environmental influences on FI, Study 3 examined the effect of distraction (television viewing, TVV) while eating and pubertal status on food intake after a pre-meal glucose drink in girls. In Study 3, TVV had no effect on FI, however, glucose suppressed FI more with no TVV compared with TVV (24% vs. 10%). In postpubertal girls, glucose reduced FI by ~27% in both the no TVV and TVV conditions, but in peripubertal girls, reduction in FI was 22% without TVV and only 1% while TVV. Thus, the results of this research support the hypothesis that physiological and environmental variables are both independent and interactive in determining FI in children and adolescents during puberty.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/65714 |
| Date | 13 August 2014 |
| Creators | Patel, Barkha Pravin |
| Contributors | Anderson, G. Harvey |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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