Diet and lifestyle are key factors in human health. We are often aware that an unhealthy diet can harm our health, but it is less well known that diet can also act as a protective factor against a wide variety of diseases. Our most important advice is to ensure a varied and balanced diet. This means that you should consume as much energy through food as you expend, so you need to adjust the amount and type of food to your lifestyle and level of physical activity. If you decide to change your eating habits, do so gradually, with plenty of willpower and perseverance, and without making drastic changes. Start with small steps that will lead you to big goals.