Just like sports drinks, nutrition bars have come a long way since their popular introduction by PowerBar in 1983. Their purpose remains the same — to deliver energy portably and efficiently — but the best nutrition bars are no longer just dense rectangles of maltodextrin and sugar. As a greater number of athletes experiment with more natural fuel sources, bars have followed suit with ingredients heavy on nuts, berries, dates, chia seeds and agave syrup. Many are organic and gluten-free. The result is a better bar for athletes, one easier to digest than ever before. Here are a handful of the best nutrition bars we’re eating now.