What Are the Effects of Eating Too Much Protein?

The ongoing popularity of high-protein diets and supplements like protein shakes continues to influence dietary habits worldwide. While protein plays a vital role in maintaining muscle mass, supporting enzymatic reactions, hormone production, immune health, and providing energy, it is essential to consume it in appropriate amounts. Australian dietary guidelines recommend that 15% to 25% of daily energy intake come from protein, with an average adult needing about 0.75 grams per kilogram of body weight for women and 0.84 grams for men. For example, this translates to roughly 53 grams daily for a woman weighing 70 kg and 76 grams for a man weighing 90 kg. Most adults already obtain sufficient protein through a varied diet, despite many actively adding extra via supplements or high-protein foods. For those engaged in resistance training to build muscle, intakes up to 1.6 grams per kilogram of body weight may support muscle growth; however, beyond this, research indicates no additional benefit. Excessive protein intake, however, does not come without risks. Proteins are a source of calories, and consuming more than the body needs leads to energy surplus, which can be converted into body fat over time. Moreover, excess protein can place strain on organs, especially the kidneys, in individuals with pre-existing kidney conditions. A rare condition known as protein poisoning, or 'rabbit starvation,' occurs when individuals consume high amounts of lean meats without sufficient fats or carbohydrates, leading to severe health issues. The source of protein also matters; animal-based proteins often contain higher saturated fats, which are associated with increased risks of heart disease and certain cancers. Conversely, plant-based proteins are linked to lower risks of chronic diseases and contain beneficial nutrients like dietary fiber, which supports gut health. Achieving a balanced nutrition approach involves not just increasing protein intakes but also focusing on diverse sources and maintaining a healthy proportion of fats, carbohydrates, vitamins, and minerals. Overall, moderation and diversity in protein sources are key to supporting long-term health and well-being.