Add green tea to your diet (and not the kind that you buy in the soda aisle). Just drink one cup of plain green tea per day. I know—it’s a bit of an acquired taste. But with more vitamin C than an orange, a boatload of antioxidants, and potential weight-loss benefits, why not make this one simple change? Think of it as a power food. And if you swap out one can of soda for green tea, you’ve got a one-two power-punch.