What would be the least amount of fat you can eat in a healthy diet?

Lesser the better: As long as your diet has ample proteins and complex carbohydrates, the fat will take care of itself. Some cooking oil is all you need and this should be in the form of olive oil or canola oil. Good source of proteins are eggs(especially the egg whites), nuts, low fat yogurt, nuts and soy products like tofu. Add regular daily exercise to it, you will have a recipe for good health.