| Popis: |
This thesis examined the effects of breakfast consumption and its subsequent influence on blood glucose levels, cognitive functioning and mood in healthy young females. The impact of a sucrose containing drink, or a placebo, and breakfast meals varying in macronutrient content were assessed. No single dose of sucrose was beneficial across all measure of mood and cognitive performance. However, individual differences in glucose tolerance were clearly an important factor. Falling blood glucose levels were associated with enhanced mood and cognitive performance throughout the test session. The impact of breakfasts differing in macronutrient contents were systematically investigated in two subsequent studies. Again glucose tolerance was an important factor. Low blood glucose levels throughout the morning were associated with enhanced memory performance. In addition, it was demonstrated that the critical aspect of breakfast for enhanced cognitive functioning and mood was the amount of carbohydrate present. Following the meta-analysis of all studies, it was demonstrated that 20.1-35g of carbohydrate was the optimal dose, and that doses of 50g and above were detrimental to mood and performance after two hours. Two subsequent studies investigated the nature of the carbohydrate consumed within the breakfast. Two types of carbohydrate were investigated, Rapidly Available Glucose (RAG) and Slowly Available Glucose (SAG). It was concluded that the SAG breakfast, that failed to induce a great change in blood glucose levels over time, significantly improved memory. Individual differences in glucose tolerance were again of importance. It was concluded that amount of carbohydrate and type of carbohydrate consumed at breakfast is crucial in enhancing cognitive functioning and mood throughout the morning. In addition, the interaction between the carbohydrate consumed and the glucose tolerance and physiology of the individual must also be taken into consideration. |
