How Many Protein Shakes a Day? 1, 2, 3 or More?

Protein shakes are a quick and easy way to increase the amount of protein in your diet. But how many should you actually be drinking? And how many is too many?

There are no rigid rules that dictate exactly how many protein shakes you should have each day. But for most people looking to build muscle, it’s probably going to be somewhere between 1 and 3 protein shakes per day.

Having more in a single day isn’t necessarily going to have any detrimental effects on your health. But you don’t want to get into the habit of living off supplements, not for any great length of time anyway.

In the long run, you’ll benefit from getting as much of your protein for the day from whole foods as you can. Solid food will often provide your body with more in the way of vitamins, minerals and other nutritional benefits, as well as helping to fill you up.

How Much Protein Do You Need?

The number of protein shakes you should have in a day depends on two things:

• Your dietary protein requirements.
• The amount of protein you get from other sources.

First, you’ll need to work out what your daily protein requirement is. That’s going to depend on how much lean muscle you have, and the amount of training you’re doing. 

A guy who weighs 225 pounds at 15% body fat, doing 5-6 hours each week of heavy strength training, is going to need a lot more protein per day than someone weighing 50 pounds less going for the odd jog now and again.

For most people wanting to maximize gains in muscle size, you’re going to need at least 0.7 grams of protein per pound, or 1.6 grams of protein per kilogram of body weight.

The number of protein supplements you should have in a day is whatever number is required to hit that daily protein target.

Let’s say, for example, that you’re consuming a balanced diet, getting all the protein you need from the food you eat.

And let’s also assume some of that comes from whole food sources like fish, eggs or milk, which are all sources of high-quality protein and rich in essential amino acids.

Do you need more on top of that? Not really.

As long as your protein intake is distributed throughout the day (as opposed to eaten in one or two large meals), adding shakes to a diet that’s already providing an optimal protein intake isn’t going to help.

However, let’s say that you’re getting around 100 grams of protein each day from the food you eat. But you’ve worked out that your daily protein intake should be around 140 grams per day, and you have neither the time nor the inclination to get those missing 40 grams from food.

In this case, drinking a protein shake or two can help you bridge the gap between what you are eating and what you should be eating.

Paired with an effective training program and a lot of hard work, the extra protein will make a difference to the speed at which muscle is gained.

Dietary Supplements Versus Whole Food

The total amount of protein in your diet is important when it comes to losing fat and building muscle. But the source of that protein – assuming that some of it comes from high-quality sources – matters a lot less.

A protein shake is just a convenient way to increase the amount of high-quality protein you get from your diet. 

To get 20 grams of protein from a chicken breast, for example, you’d need to put the chicken breast in the oven, wait until it was cooked, and then eat it.

The total amount of time required to get 20 grams of protein into your system is going to be somewhere in the region of 30 minutes.

Mixing up and drinking a protein or meal replacement supplement is faster, easier and a lot more convenient. You fill a glass with water, add a scoop of protein powder, mix it up with a fork, and drink it. That’s not going to take much longer than about 5 minutes.

It’s quick and it’s easy.

Protein shakes also contain a relatively small number of calories. With a whey protein supplement, for example, you get protein and very little else in the way of fat or sugar.

Most protein-rich foods will typically be higher in carbs and fat, so you end up consuming more calories to get the same amount of protein.

On a per serving basis, the protein shake will probably work out a lot cheaper too. 

To repeat, the total amount of protein in your diet is important when it comes to building muscle. But the source of that protein – assuming that some of it comes from high-quality sources like fish, eggs or even some plant-based proteins – is a lot less critical.

Whey Protein vs Milk

There was an interesting study done by a team of Norwegian researchers, who took two groups of untrained men and women, and got them to lift weights three days a week for three months [1].

One group took a whey protein shake twice a day, while group two got the same amount of protein from milk.

The result?

Both groups gained around the same amount of muscle. Whether the protein came from milk or whey didn’t seem to matter too much.

Even with the use of various sophisticated methods – including DEXA, MRI and ultrasound scans – to measure changes in muscle size, the researchers could find no significant differences between the milk and whey groups.

Another trial, this time by a team of US researchers, compared the effects of three different protein supplements – a whey protein concentrate, a whey protein concentrate high in lactoferrin, and hydrolyzed whey [2]. There was also a control group that didn’t take any protein 

All four groups followed the same training program, which involved lifting weights four times a week using an upper/lower split. Participants consumed 2 protein drinks a day, with each shake supplying 30 grams of whey protein. 

On training days, the supplements were taken immediately before and after training. On rest days, they were consumed between meals.

Although the researchers thought that subjects given whey protein would gain the most muscle, that isn’t what happened.

On top of a diet already providing an adequate protein intake, whey protein was no better than a placebo for increasing muscle mass in trained young men.

Do You Need a Post Workout Shake?

One of the arguments in favor of protein supplementation, particularly supplements containing whey, is that the protein gets into your system a lot more quickly than it does with food. 

The theory is that you’re better off taking a supplement rather than eating a meal after training. The protein is available to your muscles a lot more quickly, which helps to speed up the process of repair and recovery.

Is there any truth to this claim?

It’s true that whey protein is digested relatively quickly, with an absorption rate of somewhere between 8 and 10 grams per hour [3]. But this doesn’t matter too much in the grand scheme of things.

It’s not critical to get protein in your system immediately after training.

In fact, resistance training to the point of fatigue makes muscle tissue more sensitive to protein for at least 24 hours, rather than solely in the hours after exercise. The post-training “window of opportunity” stays open to protein for a lot longer than was once believed [4].

There are some instances where I think it’s useful to take a scoop or two of protein immediately after a workout.

If you’re doing fasted weight training first thing in the morning, for example, and won’t get the chance to eat until lunchtime, then taking a protein shake after exercise is a good idea.

But in most cases, the immediate provision of a rapidly digested source of protein after training isn’t hugely important. The speed at which protein is absorbed matters a lot less than your overall protein intake for the day. 

How Protein Supplements Fit Into Your Daily Diet

There are a couple of different ways you can incorporate protein supplements into your daily diet.

• To top up the protein content of an existing meal.
• As a replacement for a protein-rich meal.

There’s a sweet spot in terms of the amount of protein you want in each meal. Too little, and protein synthesis is unaffected. Too much, and your body’s ability to synthesize new muscle protein is overloaded. 

If the meal you’re eating happens to be on the low side in terms of protein, you can use a supplement to top up the amount of protein that meal provides.

For example, you might have a salad that contains only 10 grams of protein, which is below the level required to maximize muscle protein synthesis.

But what you can do is use a protein drink, providing somewhere in the region of 10-20 grams of protein, to top up the amount of protein it provides.

When it comes to building muscle, an even and frequent distribution of protein tends to work better than a skewed and infrequent one.

What that means is that you’re better off spreading your protein intake across 3-4 meals, rather than trying to cram it into one or two larger ones. 

But for a lot of people, eating multiple meals throughout the day isn’t always practical.

That’s where a protein supplement can help. 

A mid-morning protein smoothie, for example, might provide anywhere between 20-40 grams of protein, on top of all the nutrients and vitamins from the fruit. It’s quick, easy and a lot more convenient than trying to get the same amount of protein from whole-food sources.

Protein and Weight Loss

While protein is often associated with muscle growth, it’s also has a number of important roles to play when it comes to weight loss.

Other than resistance training, getting enough protein in your diet is probably the single most important thing you can do to gain (or even just retain) muscle while you lose weight.

Protein also does a better job at filling you up than carbohydrate or fat, which makes it easier to create the calorie deficit required for weight loss.

However, while protein shakes do have an advantage in terms of convenience, they do have some downsides.

Getting your protein from whole food sources means provides your body with a more diverse range of minerals, vitamins and other nutrients, which are important for keeping you healthy.

Whole foods also do a better job of filling you up than a protein supplement, so you’ll feel fuller for longer. In most cases, 30 grams of protein from food is going to be a lot more satiating than 30 grams of protein from a supplement.

Whey, Casein, Soy or Pea? Which is Best?

There are plenty of options out there when it comes to protein supplements, including:

• Whey
• Casein
• Pea
• Hemp
• Rice

Some will contain a mixture of different ingredients, based on the (largely unproven) idea that a blend of different protein sources will give you better results than using just one.

If I had to choose one, it would be whey. Whey is high in essential amino acids, which are important for building muscle.

What’s more, when it’s been compared to other types of protein in terms of its effect on muscle growth, whey will typically either outperform them, or do just as well.

It’s also relatively cheap and mixes easily with water.

However, as long as your overall diet provides enough in the way of high-quality protein, your total daily protein intake matters more than the individual supplement you’re using.

Some vegan protein sources, pea in particular, have been shown in some studies to work just as well when it comes to building muscle [6].

Questions and Answers

How much whey protein can you have in a day?

If we assume that you’re having 1-3 protein drinks each day, with each drink containing 30-40 grams of whey, you’ll be getting through between 30 and 120 grams of whey per day. 

Is it a problem if you have more now and again? No. But you don’t want to get into the habit of relying on supplements to the extent they displace whole food sources of high-quality protein.

Should you drink protein shakes on rest days?

It’s on your rest days that your body is busy repairing damaged muscle fibers, as well as synthesizing the new muscle protein that makes each muscle fiber larger than it was before. If you need supplements to help you hit your daily protein requirements, then you’ll need a supplement on your rest days as well as your training days.

Is too much protein dangerous?

In terms of muscle growth, the average person isn’t going to see much benefit in going above 0.7 grams of protein per pound of bodyweight per day. But taking more isn’t necessarily dangerous – even with a daily intake of around 1.5 grams per pound of bodyweight, research shows no evidence of any adverse effects [5].

Final Thoughts

There is an upper limit to the amount of protein your body can use for muscle protein synthesis. Once you hit that limit, extra protein isn’t going to help you build muscle any faster.

As long as you’re getting enough high-quality protein from real food, you can build muscle without the need for supplements. 

They do make hitting your protein targets for the day convenient and easy, which is why I drink 2-3 shakes a day myself. But think of them as an optional extra, rather than a strict requirement.