If you only eat eggs every day for a week, what happens to your body on the first day? You will lose weight. Eggs are rich in protein, which can increase satiety and reduce appetite. By including eggs in your diet, you can better control your appetite, which can help you lose weight. The next day, you'll gain muscle mass. Eggs are one of the most complete amino acid protein foods. Each egg contains 6 to 7 grams of protein, which helps to increase muscle mass.