Yes, you can gain weight from consuming too much protein. Excess protein is converted into glucose or fat for energy storage if your body doesn't need it for repair or building muscle.
While protein is essential for building and repairing tissues, it's important to understand how your body processes it. When you consume more protein than your body needs for these functions, the excess doesn't simply disappear. Instead, it undergoes a process called gluconeogenesis, where it's converted into glucose (sugar). If your body doesn't need this extra glucose for immediate energy, it's then stored as glycogen in the liver and muscles. Once those glycogen stores are full, the remaining glucose is converted into fat and stored in adipose tissue, leading to weight gain. Therefore, even though protein is often associated with weight loss or muscle gain, consuming excessive amounts without balancing your overall calorie intake can contribute to weight gain just like excess carbohydrates or fats. It's all about energy balance: calories in versus calories out.
Focus on a balanced diet with adequate protein intake based on your activity level and fitness goals, rather than solely focusing on high protein consumption. A registered dietitian can help you determine the right amount of protein for your individual needs.