Protein is a vital part of any healthy meal plan, as its main responsibility is to build and repair the tissues in the body. Proteins that come from plants, like legumes, contain fiber, while animal proteins, like meat, poultry and seafood, contain fat -- both of which cause a slowdown of the digestion of these proteins.
The digestive process begins in your mouth and ends in your small intestines after passing through the esophagus and stomach. The liver and the pancreas are important to the digestive process as they create the digestive juices called enzymes that help break down food. After an average meal, the stomach and small intestine are nearly half empty after two and a half to three hours. In four to five hours, the stomach is totally empty, although it could take anywhere from 24 to 72 hours for the remainder of the food to complete the digestion process.
Enzymes are responsible for breaking down food into its individual components, like protein, fat, carbohydrates, water, vitamins and minerals. Your body is then able to absorb them and use them for energy or to build or repair cells. The enzymes secreted in the lining of your stomach Break down simple foods like sugar before they reach the small intestines. Proteins, however, are complex molecules that need several different enzymes to break them down completely, keeping them in the digestive tract longer. As a general rule, carbohydrates move quickly through the stomach, protein takes a bit longer and fats spend the longest time to work their way through the digestive system, according to the National Digestive Diseases Information Clearinghouse.
Meat, poultry, seafood, eggs, dairy products, legumes, nuts and whole grains are all good sources of protein. Legumes and whole grains contain fiber, which helps to slow down their trek through the digestive system. Meat, dairy and nuts contain fat, which has the biggest impact on the time it takes to digest the food. Because of the high fat content, red meat generally takes longer to digest than poultry or seafood. Whole milk and cheeses have a higher fat content that their low-fat counterparts, and egg yolks contain more fat than egg whites. Nuts are also a high-fat food that takes a while to digest.
Although red meat is a good source of protein, it also contains a fair amount of fat. According to the Harvard School of Public Health, a 6-ounce porterhouse steak contains 38 grams of protein, but also 44 grams of fat with 16 grams from saturated fats -- roughly 75 percent of the recommended daily intake. An equivalent amount of salmon contains 34 grams of protein and 18 grams of fat with only 4 grams from saturated fats. Compare that to legumes that are rich in both protein and fiber but low in fat. A 1-cup serving of cooked lentils, for example, contains 18 grams of protein and less than 1 gram of fat.
Despite their high fat content and slow movement through the digestive system, the National Institute of Diabetes and Digestive and Kidney Diseases’ Weight-Control Information Network states that eating red meat in small amounts and choosing lean cuts have a place in a heart-healthy meal plan.
- National Digestive Diseases Information Clearinghouse: Your Digestive System and How it Works
- Colorado State University: Gastrointestinal Transit: How Long Does It Take?
- King Institute: How Long Does it Take to Break Down Meat? (PDF)
- Harvard School of Public Health: Protein
- Weight-Control Information Network: Weight Loss and Nutrition Myths
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