The digestive system involves a number of different organs throughout the body, including the mouth, stomach, intestines, liver and gallbladder, that work together to convert food into nutrients your body needs. The foods you consume can be made up of the same core group of macronutrients — carbohydrates, proteins and fats (and alcohol). These macronutrients serve as fuel for the body’s essential processes.
Some of these macronutrients are easier to digest than others. Carbohydrates, for example, are generally the quickest-digesting of these three major nutrients. That’s because they're made up of sugars, and the smallest of these simple molecules — glucose — can cross cell barrier membranes to be used as fuel immediately. Starches are made of large quantities of glucose molecules, which usually translates to very fast digestion. (Though it’s important to note, whole grains are not as digested as quickly as refined grains, as whole grains like brown rice have fiber which helps slow the absorption of glucose.)
While carbs are made up of simple sugars that break down relatively quickly, proteins are much more complex molecules. The process of dismantling and reducing the proteins to amino acids takes more time, so protein foods take longer — and therefore aren’t as “easy” — to digest.
But just because certain proteins might not be as “easy” to digest isn’t necessarily a bad thing. A lengthened digestion process makes protein-rich foods a smart and satiating option in the diet for those trying to lose weight, as it may help keep you fuller longer. Plenty of protein in the diet on a daily basis is also essential for things like muscle recovery and muscle protein synthesis in athletes and bodybuilders. Lastly, people with blood sugar control concerns can benefit from protein being a slower digesting nutrient as it can help with reducing absorption time of carbohydrates.
That said, if you’re someone with digestive issues or a sensitive stomach, then you might want to be conscious of the type of protein you consume and choose easier-digesting proteins.
What is the easiest protein to digest? Is animal protein easier to digest than plant protein?
In general, animal proteins tend to be more easily digested by our bodies than plant protein . A 2019 study published in the peer-reviewed journal, Nutrients, compared the anabolic properties of plant protein to the anabolic properties of animal protein in an effort to determine the ability of these proteins to help maintain skeletal muscle mass in healthy people (particularly, healthy older people). Researchers confirmed that plant-based proteins have less of an anabolic effect than animal proteins due to their lower digestibility. Because a lower proportion of the amino acids in plants actually end up getting digested, they aren’t absorbed and utilized for things like muscle-building as efficiently. (When you consume animal protein, you’re getting a complete source of protein. Plant protein, on the other hand, is not a complete protein.)
Additionally, there are certain ingredients common in plant-based protein sources that can possibly cause indigestion. For example, a plant protein like soy can cause gas, bloating and discomfort in some people — all indicators of slower absorption and digestion. Plant-based proteins are also high in fiber, which can cause an upset stomach if your body isn’t used to consuming increased amounts of fiber. (However, once your body adjusts, you’ll find the extra boosts of fiber — which is only naturally-sourced from plants — to be a good thing for your gut health.)
This isn’t to say plant protein can’t be digested by your body, or that you must only consume animal proteins for easy digestion. Individuals who consume animal products can benefit from consuming a wide variety of protein sources, both animal and tolerated plant-based, throughout the day to meet protein and other nutrient needs. Those who follow a vegetarian or vegan eating pattern should be mindful and deliberate about choosing a variety and adequate quantity of plant-based protein sources to meet daily needs.
Even though plant proteins aren’t as easily digestible as animal proteins in general, there are a handful of plant-based proteins that are digested efficiently. Beans like mung beans and chickpeas are great sources of protein that are both 1) plant-based and 2) easy on the digestive system. There are also plant-based protein powders made from vegetables that are good sources of protein, like yellow peas. These veggies are easy to consume and digest, and they contain a number of health benefits. (Though research published in the Journal of Renal Nutrition in 2017 under the title The Appeal of Pea Protein notes that pea protein does contain high levels of purine, which may lead to a gout flare up in susceptible patients or produce some gastrointestinal upset or distress.)
When it comes to animal protein sources, you may be wondering what meat is the easiest to digest. Lean animal proteins (like chicken breast or fish), egg protein and milk proteins like whey protein are all easily digestible protein.
Some animal proteins to avoid if you have digestive issues or concerns? Red meats. Large amounts of fatty foods like red meat make your stomach empty slower, causing bloating or discomfort.
To get more protein in their diets, many people turn to protein powders to create easy-to-drink protein shakes or smoothies. Not only can protein be more convenient to consume in liquid form, it’s also easier on digestion: Protein powders are a faster-digesting protein source compared to pieces of meat, which is great news for people with digestive issues or sensitivity or those who have difficulty meeting nutritional needs due to poor appetite.
Whey protein is one of the most commonly-used proteins for protein powder. It contains all of the essential amino acids and is easily digested. Although meat is a quality protein source, it does take longer to digest than protein powder. Rather than take a sip of a liquid protein shake, the process of digesting food begins with chewing. Chewing is necessary to help break down things like the tough meat fibers and mix the food with saliva, which kickstarts the digestive process. Eating a piece of meat requires more energy to digest and can even slightly raise the metabolism due to the amount of energy required to break the meat down. With protein powder, there’s no tough fibers to break down; the protein source that makes up the powder is already broken down, making for easier digestion.
Not all protein powders are created equal, and a blend that works for one person could very well cause indigestion in someone else. Whey protein concentrate and casein, for example, contain lactose which could cause symptoms of intolerance in individuals with lactose allergies or sensitivities.
If you still have difficulty digesting protein shakes, you can also consider adding supplements with digestive enzymes into your diet to assist your digestive system and help your body absorb those necessary nutrients even easier.
If you’re experiencing any of the following symptoms, it may indicate you’re having digestive issue or have digestive sensitivity:
Bloating and discomfort within 20 minutes of completing a meal
Getting full very quickly on a small amount of food
Gas (belching or flatulence)
Sound similar? If so, try switching to an easier-to-digest protein, or add probiotics or more fiber to your diet to aid gut health and regulate digestion.
To pinpoint the source of your digestive issues, you can also try cutting out certain foods and seeing if the exclusion of that food eliminates some or all of the above symptoms. The culprit of your digestive issues may not always be a meat source: Dairy is a food group that can be difficult to digest, thanks to lactose (the sugar found in milk and other dairy products). When lactose isn't digested properly, it can lead to gas, bloating and discomfort. If you’re someone who has a hard time digesting dairy products, you might be lactose intolerant. You can have plant proteins and animal proteins, but you’ll want to steer clear of protein sources with dairy.
Gainful can help you find a protein powder that’s personalized for your body’s needs. When matching you with a protein powder, Gainful keeps any digestive issues or sensitivity in mind, so you’ll have a protein powder that’s optimized for you. Start by taking Gainful’s quiz, where you can select your preferences and restrictions and choose your overall wellness goals. Then Gainful will take care of the rest. And with Gainful’s Flavor Boosts, you can create a protein powder that not only matches your dietary preferences but your taste buds, too. The Flavor Boosts are gluten-free, soy-free, and contain 100% natural flavors — no added sugar or sweeteners.
To get your Flavor Boost, you just have to take Gainful’s quiz to create and personalize a protein blend, then choose the flavors you’d like to add to your shakes. Your order will include unflavored protein and single-serving Flavor Boost sticks that you can mix in your drink to create a protein shake. Think flavors like Chocolate Peanut Butter, Madagascar Vanilla and Strawberry Cream.
If you have any questions about how your protein powder might affect your digestion, you always can reach out to Gainful’s personal Registered Dietitians, who are available to answer any questions you may have, whether it’s about the digestibility of your protein powder, finding a good source of protein, weight loss or just healthy eating in general.
Gainful is here to help make taking your protein — and, of course, digesting it — easy.