At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your healthcare provider or a registered dietitian, especially if you have an underlying health condition. What Is the Dr. Oz 21-Day Diet? Celebrity physician Dr. Mehmet Oz created the Dr. Oz 21-Day Weight-Loss Breakthrough Diet, a three-week diet plan intended to "jump-start" weight loss followed by a balanced, low-calorie diet for long-term weight management. The diet recommends eating plant proteins, non-starchy vegetables, and healthy fats to promote weight loss. Like most weight loss diets, initial weight loss will be water weight, and people who resume their previous way of eating after the 21-day plan will quickly regain weight that was lost.What Experts Say"Dr. Oz’s diet emphasizes nutrient-dense plant-based foods. However, the diet is quite restricti...