Recently, it has become popular again for weight loss and diabetes. It's often promoted as a “fat-burner” and natural appetite suppressant. In fact, there’s even an apple cider vinegar diet, which involves taking one to three teaspoons of apple cider vinegar or apple cider vinegar pills before each meal. But there's a lot you should know about apple cider vinegar if you're considering taking it. Find out about the research, benefits and possible side effects. Apple Cider Vinegar: What You Need to Know.