Cardiovascular disease remains one of the leading causes of death globally. Conflicting information regarding optimal nutritional intake and balance for cardiometabolic health has often led to confusion and lack of expert consensus. The precise nutritional profile and dietary patterns for optimal cardiovascular health are yet to be elucidated. This PhD covers a broad range of topics and aspects relating to cardiometabolic health. Chapter 1 explores maternal nutritional status during pregnancy, as it is a powerful contributor to the intrauterine environment and may alter offspring physiology and later life cardiometabolic risk. Therefore, we sought to determine whether maternal dietary carbohydrate quantity and/or quality during pregnancy are associated with newborn body composition and cardiac autonomic function. In chapter 2 we conducted a systematic review to determine the effect of medium-chain triglyceride oil on blood lipids. Dietary saturated fat raises total cholesterol and low-density lipoprotein cholesterol levels. However, it is unclear whether these effects differ by the fatty acid chain length of saturated fats. In chapter 3 we designed a pilot study aimed to investigate the acute postprandial effects of two different meals on flow-mediated dilation (FMD), using a randomised cross-over design. FMD is a non-invasive marker of arterial endothelial function, and the vascular endothelium is involved in early atherogenic events and regulating vascular tone. For chapter 5 we sought to determine if improved gum health resulting from periodontal intervention in Indigenous Australians with chronic kidney disease would increase consumption of healthier foods and have reciprocal benefits for carotid atherosclerosis. Collectively, our findings presented in this thesis provide a rational basis for appropriately powered studies investigating the impacts of dietary composition, and dietary patterns on the cardiometabolic health of individuals throughout the life course.