The body can absorb as much protein in one meal as it can in a day, but the more food you eat, the less efficiently it is absorbed. The body’s digestive system has a limited capacity to make new proteins. If you eat an excessive amount of protein at once, then your body won’t have enough to make new ones. To be healthier, you need to take just the right amount of protein. This brings us to the question; how much protein can you absorb in one meal? It is only after knowing the exact amount of proteins you need to eat in one meal that you will start eating the right amount and lead a healthier life.
Food contains proteins, but humans do not store protein in the same way that we store fat. Our bodies are constantly using and rebuilding proteins, which we synthesize from amino acids that we eat. A diet of just amino acids will supply all the protein your body needs for a day. This is why complete proteins-those containing all the essential amino acids-are so important.
If you don’t eat enough complete proteins, your body will make them from incomplete ones; this is called “catabolizing” them. When you catabolize proteins, your liver has to break down other tissues to supply the amino acids your muscles need for repair. The resulting waste product is ammonia, and if this ammonia builds up in the blood it can poison the brain.
Should it be 50 Grams or 20 Grams?
A lot of people say that a body can’t absorb more than about 50 grams of protein in one meal. Some say it can’t absorb more than about 30 grams. But the figure I’ve heard most often is about 20. And this may be wrong, because some people who know better disagree.
How did we get from 50 grams to 20? The principal reason is that the amount of protein in meat increases with the size of the animal, and therefore so will the proportion of meat in a given quantity of food. So if you are a vegetarian and you eat a quantity of chicken and rice that contains 20 grams of protein, you will have eaten something that contains 7 grams of protein per gram of dry weight-that is, 50 grams in total.
The problem is that it isn’t really true that the kind of protein found in meat can only be absorbed by humans with the aid of an enzyme-like substance called “protease.” We are not especially well equipped to deal with large quantities of proteins raw, and most animals aren’t either. Actually there are many cases where animals use proteases to digest proteins, but only after they have already been cooked or otherwise prepared. These include some fish and crustaceans, as well as some birds.
20 grams of protein is the maximum amount of protein your body can absorb in one meal. That’s according to a new study published in the Journal of Nutrition.
The study also showed that it doesn’t matter what type of protein you eat, whether it’s from meat, eggs, cheese, or whatever else. If a meal contains over 20 grams of protein, your body will store the rest as fat (or use it to create glucose).
This isn’t the first time I’ve heard this rule (and I’m sure it won’t be the last). But it seems like every month there’s a new fad diet that claims eating more carbs or more fat will keep you lean. And as usual, there are just as many people claiming these popular diets are wrong.
So who do we believe? Well, when it comes to calories and weight loss, I tend to side with science. So let me explain why 20 grams of protein per meal is actually correct.
The vast majority of studies on protein absorption and protein synthesis show that the body can only absorb and use roughly 20-30 grams of protein in one meal. So you don’t need to eat more than this in one sitting.
In one study, subjects were fed either 10 grams or 40 grams of whey protein after a workout. The subjects who were fed the 40 grams had much higher levels of amino acids in their blood, which means they absorbed more protein (1).
But when researchers tested how much muscle protein was synthesized during the 8 hours after exercise, there was no difference between groups (2).
In other words, the body can only use so much protein in a given period of time. Anything beyond 20-30 grams is just wasted. This is why taking huge doses of BCAAs or essential amino acids will NOT “spare” more muscle tissue during a workout or speed up recovery afterwards.
The current research shows that you can only absorb and utilize roughly 20-30 grams of dietary protein at once (3). Anything beyond that is waste. The same goes for taking huge doses of BCAAs or essential amino acids (EAAs) before or after a workout.
It Depends on the Bodyweight
The amount of protein the body absorb at one time is limited. This is true for all nutrients. If you eat more than this limit, the excess is either burned as calories or excreted as waste. This limit varies with the size of the person, but 0.8 g/kg of body weight is a good approximation for people of normal weight. Hence, an 80 kg (175 lb) person could absorb 64 grams of protein in one sitting.
What is more important to know is that muscle synthesis after training can be stimulated by eating enough protein at each meal. The previous studies show that 20-25 grams of protein per meal maximizes muscle growth after a workout. For example, eating 20 grams of beef at each meal will be better than eating 40 g at once or 10 g four times per day.
The body only absorbs a certain amount of protein in one meal, usually between 0.15g to 0.25g per pound of bodyweight. So if you weigh 200 pounds and you need 80g of protein, you can eat this in one meal or two meals or four meals; it doesn’t matter as long as you get it all in the same day.
The only exception to this is when you are trying to increase your muscle mass. In that case, having more meals (more often than every 4 hours) might be better since it gives your muscles a steady supply of amino acids, which will help them grow faster. But for any other purpose, it’s irrelevant how many times you eat as long as you get the right total each day.
The Right Amount of Protein at Each Meal and How it Looks Like?
Protein is not just for the carnivores among us. People eating plant-based diets can get more than enough protein as long as calorie intake is adequate.
Studies have shown that getting about 0.4g/lb of body weight (1g/kg) of protein at each meal is ideal for promoting muscle growth with resistance training. This amount is equivalent to roughly:
- 25-30g of protein for a 150lb person
- 35-40g of protein for a 200lb person
If you’re new to strength training, you’ll want more protein per meal because your body doesn’t use it as efficiently. Athletes and folks who are overweight also need a little extra oomph in the form of extra calories and protein.
So what does this look like? Exact quantities will vary, but here are some examples:
- 3oz salmon + 1 cup quinoa + 2 cups roasted veggies = ~35g protein
- 1 cup beans + 1 cup brown rice + 1 cup raw spinach = ~30g protein
- 10oz tofu + 2 cups broccoli = ~45g protein
