Fresh fruits are an essential part of a healthy diet because they are a great source of vitamins, minerals, phytochemicals and fiber. But if you want to lose weight you should keep an eye on the sugar content of certain fruits. Eat up on seasonal fruits like peaches, pears and berries, but be cautious of all year available fruits like grapes.They are high in sugar – that’s why kids usually like them so much – and you easily overeat on them.