The Effect Of High-protein Breakfast On Food Intake, Appetite And Body Weight

Objective:Over1/5of the children are overweight or obese worldwide. However, there is a great lack of effective intervention. Because of the need for growth and development, it is difficult to have the children on diet. Due to poor compliance, physical exercise is not practical. There is no effective drug. Due to variety of complications, Bariatric surgery has not been widely used. Calorie regulation seems a promising strategy for treating patients with childhood obesity. High-protein diet may promote weight loss. Yet, there is very limited study in Chinese adolescents. We will investigate the effect of high-protein or high-carbohydrate breakfast on the subsequent lunch-time food intake, appetite hormones and weight loss in obese adolescents, with the hope to treat obese children more effectively.Methods and materials:One hundred and fifty-six obese Chinese adolescents were enrolled,80male and76female, age averaged at14years old, body weight at58kg, and body mass index (BMI) about32kg/m2, randomly assigned to one of the two iso-energetic breakfasts:egg (n=81) or steamed bread (n=75). There are two sections for this study:the first one has one week apart; the second one has3months apart between two tests. On the test day, the subjects went through body weight, height, VAS and fasting blood draw, and were given the iso-energetic breakfasts. Visual analog scale (VAS) was performed before breakfast,30,60,120,180minutes after the breakfast to evaluate their hunger, satiety, predicted food intake etc. Blood were collected before breakfast, and30and180minutes after breakfast, to test PYY, GLP-1and ghrelin levels with radioimmunoassay. Four hours later, the subjects were given calorie labeled lunch buffet. The subjects were then discharged and suggested to eat as similar as possible to that at the test. The2nd test was performed1week and3months respectively. Analysis was performed between tests and groups. Pearson correlation was used for association. Results:For one week:there is no difference between two tests, no difference for body weight change between egg and steamed-bread groups. The subjects didn’t report significant hunger3hours after egg breakfast but there is significant PYY increase. For3months:there is no difference between two tests, but subjects with egg had more weight loss (3.9%vs.0.2%, p<0.001). This is associated with lunch-time food intake (r=-0.76, p<0.001):subjects with egg breakfast had much less (451vs.567kcal). Two and3hours after breakfast, there is difference for hunger and satiety between two groups. The subjects with egg breakfast had significant satiety (p<0.001). Body weight changes are associated with appetite hormones changes:three hours after breakfast, subjects with egg breakfast had significant increased PYY level (66%vs.18%, p<0.001), which is positively associated with body weight loss (r=0.89, p<0.001). Three hours after breakfast, the subjects with egg had higher GLP-1level (6.6%vs.1.1%, p<0.001), which is positively correlated to weight loss (r=0.78, p<0.001). Ghrelin decreased further in subjects with steamed-bread (-1.1%vs.-20.6%, p<0.001after30minutes;-5.9%vs.-15.1%, p<0.001after180minutes), which is negatively correlated to weight loss (r=-0.76, p<0.001).Conclusion:High-protein breakfast promotes weight loss in obese Chinese adolescents, possibly through its regulation of satiety, subsequent food intake and appetite hormones.