Nutrition and Energy Balance clinical trials

Acute Responses to Dietary Carbohydrate Manipulation

Sugar is perceived negatively, leading to government taxation and targets to reduce consumption. These actions have been taken based on the limited evidence that high-sugar diets are associated with greater total energy intake. However, energy intake comprises just one half of the energy balance equation (e.g. balance = intake - expenditure). Without considering energy expenditure, it is impossible to understand the effects of sugar on health. Sugar, and perhaps total carbohydrate intake, may be important for energy balance - perhaps by stimulating increased energy expenditure. Understanding dietary regulators of energy balance is more important than ever before, because diseases like obesity are a consequence of energy surplus (i.e. energy intake > energy expenditure). No studies have investigated a causal role of dietary sugar or carbohydrate on energy balance. The proposed research will seek to understand the acute (e.g. 24-hour) responses to manipulating dietary carbohydrate and sugar content on energy balance and health. This research will contribute to enabling individuals to make informed dietary choices about carbohydrate and sugar consumption. To achieve this, healthy non-obese adults will be recruited to a randomised crossover study. Measures of energy intake, energy expenditure, metabolic health, appetite, food preference, and gut microbiota will be taken. All laboratory trials will take place at the University of Bath. Three diets will be investigated: 1. Control - reflecting the composition of a typical European diet 2. Low sugar - the same composition of a typical European diet but with <5% energy intake from sugar 3. Low carbohydrate - low carbohydrate diet with <5% energy intake from sugar and <8% energy intake from carbohydrate, replacing carbohydrate energy with fat The study will consist of a 3-day lead-in period with the control diet followed by one trial day with each diet.