Although berries are sweet, they have a low glycemic load and sugar content. You can take your pick too, raspberries, blueberries, strawberries, blackberries.
With high levels of antioxidants, berries are effective at combating the damaging effects caused by exercise, pollution and other toxins.
Have a handful as a snack or throw them into a smoothie to keep your body burning fat efficiently. Many are pretty easy to grow in a pot too if you want to have your own regular supply!