| Popis: |
Subjects with prediabetes are at much higher risk of developing diabetes than healthy subjects. Weight loss helps reduce the risk of developing diabetes in these subjects, but long-term weight loss is difficult to achieve due to increases in appetite. Consumption of fermentable carbohydrate has been shown to reduce food intake and body weight, and also improve insulin sensitivity independent of weight loss. Therefore, fermentable carbohydrates may help prevent the development of diabetes in subjects with prediabetes via a two-pronged effect. This thesis comprises three investigations which examine the effects of inulin compared to cellulose control on 1) appetite and food intake, 2) measures of glucose homeostasis and 3) a long-term randomised control trial examining the effect of inulin on weight loss maintenance. In each investigation, subjects take 30g/inulin a day following a 4-week dose-escalation period. In investigations 1 and 2 all subjects take both inulin and cellulose supplements for a 6-week period each, separated by a 4-week wash-out phase. Investigation 3 is a randomised control trial comprising a 9-week weight loss phase, during which participants aim to reach a 5% weight loss at 9 weeks, and a 9-week weight maintenance phase during which subjects are asked to maintain the weight they have lost. In this body of work I demonstrate that inulin reduces appetite, food intake and weight in subjects with prediabetes. I also demonstrate that inulin was significantly associated with an increase in early insulin secretion and GLP-1, potentially due to an improvement in the incretin effect. Inulin also appears to improve insulin sensitivity in subjects with a specific subtype of prediabetes only. Finally, I demonstrate that inulin supplementation results in significantly greater weight loss maintenance, alongside changes in body composition likely to be beneficial long-term. |
