Healthy kidneys are required for potassium excretion. If you aren’t sure if you’re at risk, ask your doctor about getting your kidney function tested. Based on how we evolved, the optimum dietary potassium intake likely greatly exceeds current and even recommended intakes. The problem is we replaced many of the potassium-rich plant foods that used to fill our diets—fruits, vegetables, leafy greens, roots, tubers—with calorie-dense junk heavy with added fats and sugars, and stripped not only of fiber but also potassium. In a traditional, mostly plant-based diet, potassium intake is high and sod...