Can Protein Make You Grow Taller?

Here's a map of average male height.

Here's a map of worldwide protein intake.

Does it look kind of similar?

Well, kind of but not really - there's plenty of other factors that go into determining height.

That being said, there is statistically significant data that animal protein intake is an important predictor of how tall you are.

Let's explore why.

Nutrition is most important factor in height other than genetics.

In a bit more than 100 years, the average height in Europe has increased by 11cm, or 4 inches.

This is much faster than any genetic evolution could possibly hope to achieve, and a main change has been major improvements in healthcare and nutrition. A limited supply of nutrition means that your body redirects resources from growth to staying alive, which has a massive effect when you are growing up.

Even in the 1900s, 60% of a household's income was spent on food - so we can conclude that the fact that people couldn't get the same level of nutrition was simply because they couldn't afford it. But what's interesting is that this change wasn't just because of increased income - the 40 years before World War 1 did not show anywhere near the same level of height increases as during the warring periods, even though the overall economic growth rates were actually lower during the wars.

This is actually a reflection of the decreasing inequality between people within these countries, which quickly brought the average height up - there are diminishing returns with nutrition, so poorer people got much larger marginal gains in height from better nutrition. In addition, family sizes could affect how much nutrition a child got: during the decreasing birth rate periods of the 1900s, a single child could get access to much more resources and better nutrition that if they had to fight a sibling for it.

It's not just protein that was part of this better nutrition: access to more food, or just more calories, played a big role. Milk was also a particularly important nutritional advantage for height, especially in mainland Europe.

So why are we talking about protein here?

Well, first of all we're a protein company, so we probably care about it.

But there's evidence that protein is the single most essential nutrient for growth, followed by vitamin A and D.

A review of 37 studies found convincing evidence that increased growth and weight in childhood is directly linked to increased protein intake as a young child. 

Protein powder itself isn't a magical fix-all ingredient - there's not enough evidence to definitely say that protein supplementation alone can make teenagers taller, but when taken into account as part of a wider diet, protein explains a lot of the height variation in the world.

A study in 2014 looked at young men from 45 European countries and found that what they ate, especially high-quality proteins from foods like milk, pork, and fish, played a big role in how tall they grew. Milk products are particularly interesting because they have an especially big effect on height, which might not be purely because of the protein they contain. 

Basically, we're pretty sure that a diet high in animal protein significantly affects height - especially in lower-income countries.

Does this really have a big effect?

You might have noticed something weird I mentioned above - why animal protein?

The following graph from Masaryk University shows the ratio of animal to wheat proteins, and their correlation with height.

Essentially, their argument is that animal proteins like milk products, cheese, and meat are positively correlated with height; but plant proteins like those in wheat, rice, and vegetables were negatively correlated with height.

That meant that total protein consumption had a weaker correlation with height in developed countries, because after reaching a certain level of nutrition, what matters more is the ratio of your protein sources.

Now this is only one of a few studies, but intuitively it seems to make sense - there's a reason there's a huge variation in average height amongst developed countries: think of the Netherlands versus somewhere like Japan.

This is also supported by the fact that not all proteins are the same.

The amino acid score looks at the amount of the least available amino acid in a protein - this is an article all in itself, but in simple terms we need all the amino acids to fully use protein, and wheat protein's rating by this score is very low, while animal proteins are very high on this scale.

On top of that, the percentage of protein we can digest from cooked meat is almost 100%, compared to 80-90% from plant proteins.

In other words, both the fact that we have a wider range of amino acids in meat and the fact that we can digest animal protein better mean that it's important to look at the source of protein, and not just the amount.

And when we account for this fact, the positive correlation is very clear about how big the effect of protein is on height.

But don't get too excited

Genetics are still the biggest determinant of height we can be sure about.

On top of that, height is distributed normally - this means that most people will be about average for their environmental and genetic condition, and just by random luck some will be much taller and some will be much shorter. Do remember that there's plenty of random variation you can't control, and even if you do everything right in the factors that you can, you'll never be certain about what happens at the end.

On top of that, the research covered here about nutrition mainly applies during childhood - in other words, having sufficient nutrition as a child is much more important than having sufficient nutrition as an adult for growth. Unfortunately for many of us, that means we're past the stage where we can have substantial height gains.

We need more research into childhood development, both physically and mentally, and hopefully as the field evolves with more information we can learn together into the future.

 

This article was heavily inspired by data and sources from Our World in Data. Please check them out if you found this article interesting!