Photo Credit Skarie20/iStock/Getty Images. Many different foods contain protein. Meat, fish, eggs and dairy are animal-based protein sources. Plant-derived proteins include soy products, beans, grains, nuts, seeds and some vegetables.hicken and beef may contain 18 to 35 grams of protein per 100 grams. Fish have approximately 15 to 20 grams of protein per 100 grams, and many fish also contain heart-healthy omega-3 fatty acids.