Final answer:
Vegans avoid all animal products and must eat a variety of plant-based foods to get all essential amino acids, as most plants don't provide complete proteins.
Step-by-step explanation:
Lacto-ovo vegetarians do not eat animal flesh but do eat milk, eggs, and cheese. Vegans, on the other hand, do not consume any animal products, including meats, eggs, or dairy products. The concern for vegans is that while plant proteins can provide the protein necessary for cellular growth, it is more difficult to obtain all the essential amino acids from single plant sources, as most plant proteins are incomplete proteins. To ensure they receive a complete profile of essential amino acids, vegans need to consume a variety of plant-based foods throughout the day. For instance, combining legumes with grains or nuts with legumes can provide a complete protein profile. Vegetarians and vegans must be attentive to their diets to get all the nutrients they need and avoid nutrient deficiencies.