Eating a poor diet reduces physical and mental health because eating healthy allows people to be more active. Two-thirds of people who eat fresh fruit and vegetables daily report no mental health issues, as reported by the Mental Health Foundation. Compare this to those who do have some level of mental health problems and have generally reported eating less healthy foods and more unhealthy foods. Feelings of well-being can be protected by ensuring that our diet is full of essential fats, complex carbohydrates, vitamins and minerals.