Studies have shown that collagen can positively impact loose, sagging skin by greatly increasing its elasticity, firmness, and thickness (source).
Some of the foods that can help your body produce collagen are chicken (and chicken skin), fish (and fish skin), pork (and pork skin), leafy greens, citrus fruits, egg whites, white tea, bone broth, and cashews.
However, taking collagen supplements may be even more efficient for improving your skin’s elasticity than eating these foods. In supplement form, the collagen is already broken down, making it easier for your body to absorb (source).
Collagen supplements may come in capsules or powders and can be found at most pharmacies, health food stores, and online.