Dr. Michael Roizen, 78, maintains a biological age of 57.6 through dietary habits. He follows the longevity and Mediterranean diets, practices intermittent fasting, and prioritizes lunch as the main meal. The longevity diet is more than just a trend; it’s a lifestyle approach aimed at enhancing healthspan—the length of time you live in good health. Central to this diet is the idea of calorie restriction without malnutrition.