Diet quality and cardiovascular disease risks in adolescents

Obesity and cardiovascular disease (CVD) risk among adolescents have become major public health concerns. Obesity rate has reached 18.4% among 12-19 year olds, and 20.3% of this age group has at least one abnormal blood lipid level. Among obese adolescents, dyslipidemia rate is troubling, at 42.9%. Diet quality may play a key role in the development of obesity and other CVD risks among this age group. Consistently poor diet quality has been observed among adolescents, and research indicates dietary patterns from this age persist into adulthood. Moreover, minimal research has explored connections between diet quality and CVD risk in adolescents. Therefore, the primary aims of this dissertation were: 1) to determine differences in diet quality between obese and non-obese, hypertensive and normotensive, and dyslipidemic and non-dyslipidemic 16 year-olds; 2) to examine relationships between diet quality and CVD risks; 3) to identify relationships between dietary components and CVD risk; and 4) to examine interactions between diet quality and adiposity on CVD risks. The first study identified greater sweetened beverage intake among obese adolescents. Additionally, fruit and fiber intake were negatively related to body mass index (BMI). Fruit and protein intake were also negatively related to waist circumference (WC). The second study found positive relationships between blood pressure (BP) and BMI and WC. Greater consumption of vegetable, fruit, whole fruit, greens and beans, fiber, and magnesium, and lower consumption of energy from fat were related to decreases in BP. The second study also showed greater intake of sweetened beverages, and lower intake of omega 3 fatty acids and fiber among participants with elevated total cholesterol (TC). Diet quality, omega 3 fatty acids, fiber, vegetable, and greens and beans were positively related to TC. Lastly, low density lipoprotein was negatively related to vegetable and greens and beans intake. Significant moderation effects by diet quality were observed on the relationships between BMI and systolic BP, and BMI and triglycerides. These findings implicate elevated BMI, WC, and sweetened beverage intake with greater CVD risk. By contrast, these findings suggest cardio-protective effects for greater vegetable, fruit, and fiber consumption