RecruitingClinical trialWestern Diet on Cardiometabolic and Immune FunctionThis study will implement a Western Diet (WD) to understand cardiometabolic and immune function in middle-aged adults (50- 64 years old). Vascular health, intestinal permeability, and T-cell function will be examined before, during, and after the WD. The WD is a 10-day diet and will consist of 25% of total energy from added sugars.