SNAC Study- Satiety, Nutrition and Appetite in Children

INTERVENTION: Macronutrient specific meal‐ High carbohydrate or high protein in obese children. The breakfast meals will be a milkshake. The energy content of the milkshake will be 25% of the participant's estimated energy requirements. The high carbohydrate will consist of 6%protein, 16% fat, 75% carbohydrate. The high protein will consist of 55% protein, 15% fat and 28% carbohydrate. There will be two study mornings. On the first morning they will receive either one of two study breakfasts (high carbohydrate or high protein). They will then be asked to come back on a second morning after a minimum of 1 week washout to cross over and receive the alternate study meal. CONDITION: Obesity PRIMARY OUTCOME: Energy intake (kj) at the subsequent meal and energy intake from everything consumed post lunch until lunch the next day. ; ; We will assess the kj consumed at lunch by weighing out the amount of lunch supplied minus the amount that is left over. ; We will assess the amount eaten post lunch until lunch the next day by asking participants to complete a food record. We will analyse the food record using a program called FoodWorks. Postprandial changes in satiety and appetite gut hormones: ghrelin, PYY, GLP‐1, CCK. ; These will be measured using blood tests. We will collect blood samples, centrifuge the blood to obtain plasma and serum and analyse these using a Multiplex. VAS (Visual Analogue Scale) to measure hunger and fullness SECONDARY OUTCOME: Changes in energy expenditure after consuming the two different macronutrient meals in both obese and healthy weight children. Energy expenditure will be measured using indirect calorimetry. INCLUSION CRITERIA: *Healthy weight ‐ body mass index (BMI) within the 15th – 85th percentile for age and sex. *Healthy obese ‐ BMI > or = to 95th percentile for age and sex. *Non smoking *NOT taking medications or drugs known to alter body composition or metabolism, including insulin sensitisers, glucocorticoids, thyroxin *NOT have obesity due to secondary causes relating to genetic disorders (e.g Prader‐Willi syndrome, Down’s syndrome) or endocrinology‐related disorders (e.g. hypothyroidism or growth hormone deficiency) *NOT have lactose intolerance or follow any severely restricted diets or have complex food allergies