protein needs: animal and plant sources

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This chapter explores the special role of protein and amino acids in the human body. It describes how protein is the only macronutrient with nitrogen and it is continuously broken down and synthesized to meet physiological demands from the body’s pool of amino acids. The chapter discusses essential and nonessential amino acids and reviews whether “complete” proteins are required at every meal. The chapter combats nutrition disinformation, including the superiority of animal over plant proteins for health and the overstated role of high protein diets on weight loss and obesity. It critiques current protein recommendations, which vary based on age, physical activity, and health status, while clarifying that most humans are eating far too much and favoring animal proteins over healthy and sustainable plant proteins. The chapter closes on collagen, a skin-boosting protein that’s gotten a lot of hype for its anti-aging promises—but does it really work?