Do you know the difference between a nut and a seed? Are all nuts equal? Increasingly we hear how good nuts and seeds are for us, and are urged to add them to salads, smoothies and breakfast cereals.

"Nuts used to be thought of as unhealthy, but they're one of the best things you can put in your mouth," he said. Similarly, eggs and fish are nutritional powerhouses, but also high in fat.

Though technically a legume, peanuts are often treated as nuts in culinary terms ... such as omega-3 and omega-9 fatty acids, which are good for heart health," says McLellan.