Liquid Protein Preloads With Different Carbohydrate Types Effects on the Glycaemic and Insulinaemic Response

Consumption of milk proteins increase satiety and reduce glucose response when consumed alone or with carbohydrate. Milk proteins are of interest because proteins are more satiating than either carbohydrate or fat, and they regulate food intake and metabolic functions by the intact protein, encrypted peptides and amino acids on gastrointestinal and central pathways. White rice and white bread are two common carbohydrates types mostly consumed in Asia. Both of them are known to result in high glycaemic and insulinaemic responses. However, in most meals, they are accompanied by other foods such as soy milk, cow milk products. The glyceamic and insulinaemic responses are determined by the type of protein and the type of carbohydrates. And also the consumption time of protein and carbohydrate. Recent research points to an intrinsic value of small amounts of milk protein or dairy consumed shortly before a meal can reduce the glycemic response to carbohydrate and that this is not at the cost of increased demand for insulin. The objective of the present study is to investigate how glycaemic, insulinaemic and satiety responses to a white rice or white bread meal changed when a soy milk or cow milk consumed together or shortly before the meal. Whole soy milk and whole cow milk will be added to the meal. Healthy subjects (n 15) will ingest the test meals once. The meals will be provided as breakfasts, on 10 different occasions, in random order with ≥ 7 days between each. Blood samples (from the cannula and finger pricks) will be then drawn for 3 h, and glucose and serum insulin, plasma glucagon, satiety markers, inflammation markers, amino acids et.al will be analysed. The objective of the study is determining if different liquid protein consumed shortly before or with carbohydrate has different effects on metabolism. And also we will compare the difference of white rice and white bread. Determining the consuming time effect, milk protein type and carbohydrate type on glycaemic and insulinaemic are critical for the provision of dietary advice and formulation of public health guidelines.

Inclusion criteria

• Chinese ethnicity
• Age between 21-40 years
• Not on prescription medication known to affect glucose and satiety related metabolism
• Do not partake in sports at the competitive and/or endurance levels
• Weight of at least 45kg
• Body mass index between 18.0 to 24.9 kg/m2
• Normal blood pressure (120/80 mmHg)

Exclusion criteria

Smoker

• fasting blood glucose>5.5 mmol/L
• Any major medical conditions including diabetes, hypertension, cardiovascular disease, thyroid disorders
• Allergic or intolerant to foods presented in the study