Did you know that our metabolism naturally slows down by five percent a decade, after we turn thirty? Yikes! Fortunately, there are some foods that have been known to help speed up our metabolism, giving us more energy and helping promote weight loss. Sunflower seeds are a great source of protein. It’s important to include plenty of protein in our diets because this nutrient serves as the building block for all of our tissues and cells. Tuna is a very popular food with many of the world’s bodybuilders, and for good reason! It’s an excellent source of protein that helps to boost our metabolism as well as an excellent source of omega-3 fatty acids, protein, potassium, selenium and vitamin B12. Studies show that green tea can boost your metabolism, lower your cholesterol and even increase your immunity too. Grapefruit is a great way to start the day since the chemical properties in grapefruit can reduce insulin levels, boosting metabolism.