Açaí
Being rich in fiber, low in sugar, and having high amounts of antioxidants, açaí berries have proliferated in the marketplace by their seemingly countless benefits. Wait, AND they help you lose weight? That assumption may be too good to be true. Because pure açaí is basically all seeds, it's sold commercially as juices/powders and contain added sugar and calories. Compared to the price of other healthy alternatives like blueberries, maybe the açaí bowl is only worth it for taste.
[Photo via @acairoots]