This thesis describes the impact of high energy density nutritional supplement drinks (HENSDs) on appetite regulation, energy intake and cardiovascular risk factors in lean healthy females. It also explores the impact of Solid Ready-To-Use Foods (RTUF) and a milk based Liquid Ready-To-Use proprietary Supplement (LRUS) on weight gain and appetite in mild to moderate underweight children from Pakistan. The thesis consists of a literature review (Chapter 1), general methods (Chapter 2), three experimental chapters (Chapter 3- Chapter 5), each describing an independent research study, and a general discussion and conclusion chapter (Chapter 6). Accumulating evidence suggests that oral HENSDs increases energy intake and are beneficial for the treatment of malnutrition. Their effectiveness however, may be diminished by acute suppression of appetite. Therefore, the first experimental study aimed to investigate the extent to which the consumption of the HENSD in the fasted state reduces energy intake during a consecutive breakfast and lunch and whether this reduction relates to changes in appetite and metabolic appetite regulators. Twenty three young females with BMI of 18.2 ± 0.8 kg/m2 consumed either a HENSD or a low energy drink (PLACEBO) after fasting, in a single blind randomized cross-over study. Appetite was tracked, and blood taken, prior to the intake of the supplement and 240 minutes afterwards. Energy intake was recorded during an ad libitum buffet breakfast served 60 minutes and an ad libitum buffet lunch served 240 minutes post supplementation. Energy intake during the breakfast was significantly higher in the PLACEBO than in the HENSD trial. No significant difference was found in energy intake during the lunch between the two trials. When energy provided by supplements was added to energy intake during breakfast and lunch, the energy intake in the HENSD trial was significantly higher. The net effect was that total energy intake was increased by 1.07 ± 0.34 MJ in the HENSD trial. During the pre-breakfast, feelings of hunger and a desire to eat were significantly lower; satiety and fullness were significantly higher in the HENSD trial. After breakfast, none of the appetite measures differed between the trials regardless of plasma PYY, CCK, and insulin concentrations being significantly higher in the HENSD trial. The second experimental study investigated the time scale of compensation after HENSD supplementation. Over a five day period, energy intake was measured after the supplementation during the evening meal, and during the ad libitum breakfast, lunch and dinner consumed on the consecutive day. Since, consumption of HENSD due to the promotion of energy was expected to promote positive energy balance, this study also aimed to investigate the impact of HENSD supplementation on cardio-metabolic risk factors. Twenty-three young healthy females with a BMI of 18.7 ± 1.2 kg/m2 participated in a single blind randomised, controlled, crossover study. Participants consumed either HENSD or a PLACEBO for five days in the evening. Participants were asked to record their dietary intake during the days of supplementation. On the sixth day plasma lipids, insulin and glucose concentrations were measured in the fasted state and at 30, 60, 90 and 120 minutes after the ad libitum buffet breakfast and lunch. The findings showed that the average daily energy intake was significantly higher in HENSD trial and that consumption of HENSDs in the evening induced immediate and short-lasting reduction in energy intake. Fasting plasma concentrations of insulin and HOMA (IR) were significantly higher in the HENSD as compared to the PLACEBO trial. No significant differences were detected in fasting plasma concentrations of TAG, total-, HDL- and LDL-cholesterol between the HENSD and the PLACEBO trials. The third experimental study explored the efficacy of RTUFs and LRUS in promoting weight gain and their effect on appetite regulation in mild to moderate malnourished children. An open labelled randomized controlled trial was conducted in primary schools of Pakistan. Sixty eight mild to moderate underweight children aged 8.2 ± 1.2 years were randomly allocated to receive either RTUF or LRUS providing 500 kcal/ day in addition to regular diet in their school for four weeks. The children’s height, weight, and skinfolds were measured before supplementation and at the end of the supplementation. The children marked visual analogue scale questionnaires before the provision of the first and the last supplement. The findings from this study indicated that after four weeks of supplementation the average weight gain, change from the baseline in weight-for-age Z score (WAZ), height-for-age Z score (HAZ) in the RTUF and LRUS were not significantly different between the two groups. The difference in the appetite measures before the provision of the first and the last supplement between the two groups were also not significantly different. The total extra energy supplied for 4 weeks would have been expected to lead to an excess gain of 2kg. Thus, at least 2/3 of the energy ingested appeared to have been compensated by less intake at other times. Based on the data obtained the following conclusions have been drawn: • Following oral intake of HENSDs, the appetite suppressive action of the metabolic and hormonal appetite modulators is short lived. • HENSDs consumption for five consecutive days in the evening induced compensation, which happens immediately, disappears quickly and is short-lived which allows only partial compensation for the energy provided by HENSD. • Short-term supplementation with HENSD is safe in relation to the impact on cardiometabolic risk factors such as plasma concentration of fasting and postprandial lipids but can be expected to reduce insulin sensitivity. • RTUF and LRUS given to the community has similar impact on improving the nutritional status in mild of moderate underweight children but the overall rate of weight gain was lower than expected.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:646718 |
| Date | January 2014 |
| Creators | Fatima, Sadia |
| Publisher | University of Glasgow |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://theses.gla.ac.uk/6297/ |
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