If your goal is to increase your collagen intake from real food rather than supplements, I recommend drinking bone broth and eating seafood. Chicken and egg whites are also good sources of collagen, but the former is usually high in unfavorable polyunsaturated fatty acids (i.e., omega-6) and the latter contains certain proteins (e.g., avidin) that can inhibit nutrient absorption (especially when not fully cooked). Besides eating enough animal protein to fuel your body with the ingredients it needs to make collagen, you should also stay away from sugar and processed carbs. Those cause inflammation and can damage collagen.