Control your portion sizes AS Dr Khan reported, animal studies suggest that a 10-50 percent reduction in calorie intake can increase an individual’s maximum lifespan. Studies of humans show similar links between low calorie intake and an extended lifespan with a lower likelihood of disease. "Naturally, calorie restriction helps to reduce excess body weight and belly fat, of which both carry the risk of a shorter lifespan," says Dr Khan. The best vitamins: The most beneficial vitamins (Image: Getty Images) READ MORE Spicing things up According to Dr Khan, herbs and spices don’t just make your food tastier, but also have a beneficial effect on health and wellness.