The goal of this clinical trial is to determine if a self-selected high potassium diet is easier to achieve and more effective at improving vascular health than a low sodium diet in generally healthy young adults who typically consume more than the recommended amount of sodium. The main questions it aims to answer are:

1. Is it easier for young adults to increase their potassium intake, rather than reduce their sodium intake?
2. Is a self-selected high potassium diet better at improving vascular health compared to a self-selected low sodium diet?

Researchers will compare the effectiveness of an education-based intervention centered only on increasing dietary potassium intake against an education-based intervention centered only on reducing dietary sodium intake.

Participants will be randomly assigned to receive comprehensive dietary education on adopting either a high-potassium diet or a low-sodium diet.

Education will be delivered in four weekly one-on-one sessions. Following the four-week education period, participants will be encouraged to change their diet based on what they have learned. Measures of dietary compliance (urine samples and diet records) and cardiovascular health (blood pressure, endothelial function) will be assessed at two, four, and six months post-education.

High sodium diets are a major contributor to cardiovascular disease. Unfortunately, reducing sodium intake can be challenging. It is known that increasing potassium intake can improve cardiovascular disease risk factors in a laboratory setting. The investigators are hoping to show that it is more feasible and effective for individuals to increase their potassium intake, rather than reduce their sodium intake, to improve cardiovascular disease risk factors, including blood pressure and endothelial function.

In this study, participants will be randomly assigned to receive individualized education over the course of four weeks to help them adopt one of two dietary patterns: 1) a self-selected low sodium diet (goal: ≤1,500 mg/day) or 2) a self-selected high potassium diet (goal: ≥4,700 mg/day). Participants will be provided individualized nutrition education once per week, at the participant's convenience by trained study staff to help them meet the target nutrition goals. No food, supplements, or devices will be provided to participants, and participants will be advised not to take any dietary supplements containing potassium during the intervention and follow-up period. Follow up with participants will be every two months for six months post-education to measure compliance with the desired dietary changes as well as changes in cardiovascular health.

Inclusion Criteria:

• Willing and able to attend in-person laboratory visits
• Usual sodium intake ≥3,000 mg/d for females and ≥4,000 mg/d for males
• Usual potassium intake ≤2,500 mg/d in females and ≤3,000 mg/d in males

Exclusion Criteria:

• BMI ≥35 kg/m2
• Seated blood pressure ≥130/80 mmHg
• Current diagnosis or history of diabetes, renal disease, cancer, cardiovascular disease, or major cardiovascular event (e.g. heart attack or stroke)
• Current or recent use of a diuretic (within the past 6 months)
• Elevated blood lipids (LDL cholesterol ≥190 mg/dL)
• Elevated serum potassium level (>5.1 mmol/L)
• Elevated BUN (>22 mg/dL)
• Elevated creatinine (>1.2 mg/dL)
• Low eGFR (<90 mL/min/1.73 m²)
• Current or recent use of tobacco, nicotine, or illicit drugs
• Radical hysterectomy or oophorectomy (females)*
• Pregnant or lactating
• Following a weight-loss diet, or intending to gain or lose weight during the study period