Today, there are a few ways to turn back the clock. Liposuction. Collagen implants. A great haircut (bangs, anyone?). But what if you could naturally make yourself feel--and look--younger? The answer isn’t a secret or a mystery. In fact, the solution is right on our plates. The key is boosting your metabolism, the process that turns food into body fuel and controls how much of that fuel you burn.

“If your metabolism is higher, that means you’ll have more energy and feel younger and be more active,” says Dr. Eric Plasker, author of the 100 Year Lifestyle and the 100 Year Lifestyle Workout, out in December. To power up your furnace, feed it fiber, lean meats and complex carbohydrates, says Plasker.

If this sounds like a generally healthy diet, that’s not a coincidence. “The higher your lean body mass, the higher your metabolism, because muscle burns more energy than fat,” says Plasker. In other words, by getting leaner, you’ll boost your metabolism, and by boosting your metabolism, you’ll stay leaner. Start by packing on muscle and losing fat through a workout that incorporates both strength training and intervals of cardio. (Remember, always check with your doctor before starting an exercise program.) Then, fill up on the foods below.

1. Apples. An apple a day may not always keep the doctor away. But research has shown that low-calorie, high fiber fruits like apples and pears can help dieters lose weight.

2. Leafy greens. Salad stars like kale and spinach are not only rich in fiber but also calcium. “There have been studies that have linked calcium to weight loss,” says Plasker.