Even under healthy conditions, too much of any macronutrient can cause digestive discomfort. While eating too much protein poses little risk of damaging your stomach or any digestive organs if you are otherwise in good health, you may experience gastrointestinal pain if you overindulge in protein. Seek the advice of your health-care provider if you are concerned about your protein intake or if you have continuing stomach or abdominal pain.
The digestion of protein occurs in your stomach and small intestine with the help of gastric juice and a variety of proteolytic enzymes. When food protein reaches your stomach, the acidic juice denatures, or unfolds, the protein, allowing preliminary digestive enzymes to break the long protein strand into shorter pieces called peptides. The peptides travel to your small intestine and undergo further degradation by additional protein-digesting enzymes, resulting in individual amino acids ready for absorption. Eating too much protein at once can inundate your digestive enzymes with more material than they can handle, causing your digestion to slow. As the process slows, your stomach may hurt.
Indigestion describes a disorder in which your stomach area hurts while you are eating or following a meal. One cause of indigestion involves eating too much. Your body can physically move only so much food at a time as it shifts denatured peptides from your stomach to your small intestine. When you overwhelm your gastrointestinal system with a large influx of protein, you may reach your body's limit as to how quickly this process can occur. As the remaining protein sits in your stomach awaiting its turn, the large mass of unmoving food may cause your stomach to hurt. This discomfort is temporary and should resolve as protein eventually moves through your system.
Insufficient Digestive Enzymes
In addition to eating too much in general, eating too much of one specific food can cause you stomach pain. Your digestive system is equipped to handle a variety of nutrients from the foods you eat because you digest different macronutrients with specific enzymes. That is, the enzymes that digest your dietary fats cannot digest your carbohydrates; they can only digest fats. Consuming too much protein strains the capacity of your protein-digesting enzymes, limiting how much they can digest at once. In combination with the limited volume of food your gut can move when you eat too much, having insufficient digestive enzymes to process the protein can further slow the process and add to your stomach pain.
To minimize the chance of experiencing stomach discomfort from food intake, space your meals throughout the day. Avoid including far more of one macronutrient than another in your meals. Finally, drink plenty of water throughout your day, and include sufficient dietary fiber to keep your bowels regular so you do not become constipated.