Quick Answer:
Anytime you are eating more calories than you burn you will gain weight. Typically protein is a hunger suppressant however, if you are consuming too much protein, it can cause weight gain instead of weight loss. You will more than likely only be prone to overeating protein if you are taking a supplement since it would take a lot of food to over eat your protein calories for the day.
Full Answer:
Anytime you consume more calories than the amount of calories that you burn, you will gain weight. If you consume an excess amount of protein calories, your body will use what it can and it will store the rest as fat to use for another day. The American dietary guidelines suggest that protein intake be kept between 10% and 35% of daily calories. This varies depending on diet goals, activity level, and the amount of muscle recovery. If you are trying to lose weight total calorie intake is the measurement for success. Eating more protein will make you feel fuller and replace other, theoretically, bad food choices but totally daily caloric intake is what will result in weight gain or loss.
Research
According to a recent study, those who consumed over 20% of their diet in protein calories were more likely to gain weight than those who consumed less than 15% of their diet in protein calories. Those most likely to over consume protein are people who are adding protein supplements to their diet either to lose weight or build muscle. If you eat a variety of protein rich foods throughout the day you will ensure you are getting all the essential amino acids as well as not over consuming protein calories. Drinking your protein calories or eating protein bars will make it easier to over indulge.
Protein is a macronutrient that aids in keeping you full longer and boosting the body’s metabolism but too much of anything will have bad consequences. Weight gain is not the only side effect of consuming too much protein. Kidney issues, liver problems and dehydration are other side effects that you may experience. In addition, protein powders and shakes are not regulated by the FDA; so be sure to talk to a nutritionist or doctor before a drastic dietary change.
References: HealthyEating, Prevention, Livestrong, Bicycling