Six secrets to a healthy diet are: 1. Eat high-fiber foods like whole grains, vegetables, and fruits which slow digestion and control blood sugar and insulin levels. 2. Eat in moderation to get enough nutrients without overeating which can cause obesity and disease. 3. Eat a variety of foods to get different nutrients and avoid getting deficient. 4. Reduce saturated fats and eliminate trans fats which increase disease risk. 5. Adopt good eating habits like slow eating and eating with others instead of in front of screens. 6. Drink plenty of water which flushes toxins and keeps you hydrated.