Not all apples are created equal, nutritionally speaking. A Canadian study found that the darker, thick-skinned red apples such as Red Delicious have higher concentrations of antioxidants compared to Yellow Delicious or McIntosh. Also important: Freshness. “A more recently picked apple of any variety will have a higher nutritional value than older ones,” says McDaniel. Buy them at a farmer’s market if possible, or do a gentle squeeze test at the store (the flesh should feel firm).