Calories in Squash, summer, yellow, includes skin

What makes squash so powerful?

Yellow summer squash belongs to the species Cucurbita pepo, the same remarkably diverse species that gives us zucchini, pumpkins, and even some gourds. Botanically, it is classified as a pepo, a specialized type of berry with a thick, hard rind that is not easily removable. Unlike winter squashes, summer squash is harvested while immature, meaning its skin and seeds are still tender and entirely edible. This early harvest is crucial because the skin houses a significant portion of the squash's carotenoids, particularly lutein and zeaxanthin. These pigments are the same compounds that give marigolds and egg yolks their bright yellow hues. In the human eye, lutein and zeaxanthin accumulate in the macula, where they help filter out harmful blue light and neutralize reactive oxygen species. Because the flesh of yellow summer squash is mostly water—over 95 percent—keeping the skin on during cooking ensures you retain these fat-soluble antioxidants, which would otherwise be lost if peeled and discarded. Additionally, the squash's mild flavor comes from its relatively low concentration of volatile compounds compared to other garden vegetables.