How long does it take to digest a protein shake?
How long does it take to digest a protein shake? How long does it take to digest protein powder? Learn more about protein shakes, and what makes some easier to digest than others.
How fast do we digest protein?
Different types of dietary protein are digested at different rates. According to a study published in the International Journal of Sport Nutrition and Exercise Metabolism, amino acids (the building blocks of protein) are absorbed at the rate of 1.3 grams to 10 grams an hour. 20 grams of a fast digesting protein might therefore only take 2 hours to digest, whereas 20 grams of a slow digesting protein might take 15+ hours to digest.
Does protein digestion (absorption) rate matter?
Research suggests that the speed of protein digestion and amino acid absorption from the gut affects postprandial metabolic response, which is a fancy term for the complicated physiological process that breaks down food into glucose (sugar), fatty acids (fats), and amino acids (protein) and supplies our muscles with fuel. Slow-digesting protein is found to promote inhibit protein breakdown, whereas fast-digesting is found to promote protein synthesis, the process by which cells make proteins. There are therefore possible metabolic advantages to eating both flow and fast-digesting proteins.
What does this tell us about the digestion rate of protein shakes?
The study reference above only tested the impact of protein digestion rate when proteins were eaten alone, and the authors acknowledge that the presence of other macronutrients like carbohydrates and fats would have likely affected the results. Because most protein shakes contain added ingredients, this study therefore does not tell us much about how slowly or quickly you will digest your protein shake. If you drink pure whey protein isolate with nothing but water, it is safe to say that it will only take a few hours to digest, but who does that? Most protein shakes, whether they are store-bought or homemade, contain a number of ingredients that can affect that rate at which the protein is absorbed.
At this point, I would be remiss if I did not mention that unless you are Michael Phelps in his prime, worrying about slow and fast-digesting proteins is a waste to time. Any type of protein can help you reach your wellness goals, and there are far more important things to consider than protein digestion rates when it comes to protein shakes.
The truth of the matter…
Again, there are two types of protein shakes, ready-to-drink (store-bought) protein shakes, and homemade protein shakes made with protein powder. In order to make a protein shake with protein powder, you have to mix the powder with milk or water. This requires a blender or a shake bottle, and a little extra time and effort. Some people buy ready-to-drink protein shakes instead of protein powder because they value convenience, but if they knew what they were drinking, they would probably vomit.
Ready-to-drink protein shakes are full of food additives like emulsifiers, stabilizers, and thickeners. Ingredients like these help with shelf stability (sitting on the shelf for a long time without spoiling), and can replicate the creamy, dairy-like mouthfeel that people crave. Although this sounds like a good thing, food additives look nothing like real food and can cause a number of side effects. This is why I recommend that you make your own protein shakes with protein powder. Unfortunately, however, not all protein powders are created equal, and many contain the same additives found in ready-to-drink protein shakes. You will therefore have to read ingredient lists to find the good ones. Keep reading to learn more about the top ingredients to avoid when buying protein powder.
Avoid food additives.
Again, most ready-to drink protein shakes and many protein powders are full of food additives. Although not necessarily bad for you in small quantities, additives can add up quickly (especially if you drink a protein shake every day) and cause gastrointestinal (GI) side effects like bloating, constipation, diarrhea, gas, and stomach pain. This is because food additives are, generally speaking, hard to digest. They sit in your gut for longer than food should, which gives your gut bacteria more time to eat. As they eat, these bacteria produce gas, which causes bloating and stomach pain. Gas also slows colonic transit (the amount of time it takes food to travel through the colon), which can lead to constipation.
In the long term, food additives can disrupt regulatory pathways in the intestine, which can result in the development of inflammatory bowel disease (IBD) and systemic inflammatory disorders. Artificial sweeteners are among the most harmful additives in the long term as they alter the composition of your gut microbiota (the collection of microorganisms that help you digest food). This can lead to serious, chronic GI problems and widespread inflammation. Some sweeteners, especially sugar alcohols like xylitol, are also poorly absorbed by the gut (meaning they feed those hungry gut bacteria) and cause diarrhea because they draw water into your intestine. Now you finally have something to blame for those post-protein shake trips to the bathroom!
Here is a list of the most common food additives in protein powder:
acacia gum, acesulfame potassium, artificial flavors, aspartame, carrageenan, cellulose gum, dextrin, dextrose, erythritol, gellan gum, guar gum, gum arabic, inulin, locust bean gum, “natural” flavors*, maltodextrin, rice syrup solids, soy lecithin, silica, sucralose, sunflower lecithin, xanthan gum, xylitol
When it comes to identifying food additives, go with your gut. 😉 As a rule of thumb, they are the ingredients that you cannot pronounce. Food additives are not the only thing to look out for when buying a protein powder that is easy to digest, however. There are several other ingredients that can upset your stomach.
egg whites, coconut, cocoa, monk fruit
Protein Matrix Comprised of (Whey Protein Concentrate, Whey Protein Isolate, Calcium Caseinate, Micellar Casein, Milk Protein Isolate, Egg Albumen, Glutamine Peptides), Polydextrose, Sunflower Creamer (Sunflower Oil, Corn Syrup Solids, Sodium Caseinate, Mono- and Diglycerides, Dipotassium Phosphate, Tricalcium Phosphate, Soy Lecithin, Tocopherols), Natural and Artificial Flavor, MCT Powder (Medium Chain Triglycerides, Nonfat Dry Milk, Disodium Phosphate, Silicon Dioxide), Lecithin, Cellulose Gum, Salt, Yellow 5, Sucralose, Acesulfame Potassium, Papain, Bromelain.
*This is the actual ingredient list of one of the best-selling protein powders in the United States.
Dairy-based proteins like whey and casein, which are byproducts of cheese and yogurt production, are known to cause digestive issues, especially for people with lactose intolerance and irritable bowel syndrome (IBS). Over one in three Americans are lactose intolerant, and the prevalence of IBS is somewhere between 10 and 15 percent in the United States. It follows that you may be lactose intolerant or have IBS and not even know it. Irritable bowel syndrome (IBS) is a poorly understood condition, and it is unclear why dairy triggers symptoms. Lactose intolerance, on the other hand, is clearly understood. People with lactose intolerance are unable to fully digest lactose, the sugar in dairy. As you just learned, partially digested food feeds the bacteria in your gut, which produce gas.
Avoid protein concentrates and isolates.
Finding an additive-free, dairy-free protein powder is hard. Finding an additive-free, dairy-free protein powder made with real foods is next to impossible. Why? Most protein powders are made with protein concentrates and isolates, foods stripped of everything but the protein. They are listed on the ingredient list as “pea protein,” for example, as opposed to “peas.” We will not go into the details, but protein concentrates and isolates undergo heavy mechanical and chemical processing before becoming protein powder. Sometimes, manufacturers use chemical solvents like hexane to isolate (separate) the protein from the food. This means that what you end up putting into your body looks nothing like real food. The potential problem here is that your gut might not know what to do with ingredients like these. Your gut prefers the real thing, not some heavily-processed imitation, so protein concentrates and isolates might be hard to digest for people with sensitive stomachs.
Instead of protein concentrates or isolates, we use egg whites and almonds. Egg whites are simply pasteurized and dried before becoming protein powder. Almonds are just roasted, pressed, and ground. Minimally-processed ingredients like these are easy to digest and a stomach and gut-friendly alternative to protein concentrates and isolates.
Unless you have a sensitivity or allergy to eggs, egg white protein is the best protein for people with sensitive stomachs. Egg whites are low in fiber, low-FODMAP, and have the highest protein digestibility-corrected amino acid score (PDCAAS) of any whole food. Our customers have experienced fewer digestive issues with egg white protein than with any other type of protein.
If you cannot eat eggs, try our almond protein powder. Almonds are simply roasted, pressed, and ground before becoming protein powder. Unlike protein concentrates or isolates, they still contain lots of healthy fats, fiber, and other nutrients like calcium and vitamin E. We prefer almonds to other minimally-processed plant protein sources because they are more gut-friendly. Research suggests that almonds can improve the diversity and composition of the gut microbiome. Research also suggests that almonds possess prebiotic properties, meaning they stimulate the growth of healthy bacteria in the gut.
“I just finished my first bag and ordered 2 more! I Iove this stuff! I have IBS and every protein powder hurts my stomach…except drink wholesome!”
So, how long does it take to digest a protein shake? Every protein shake is different, which makes it hard to say how long it will take you to digest your protein shake. That said, by avoiding ingredients like food additives, dairy, and protein isolates, you can ensure that you are drinking a protein that is easy to digest. If you are interested, drink wholesome is the easiest protein powder to digest because it is made with stomach-and gut-friendly real foods. Order samples to see for yourself.
This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment.