You are what you eat - True or false?

Who has not heard of this saying? I think everybody has heard it at least once in his life. I would even go as far as saying that this exists in nearly every language. At least in the ones I know. But what does it really mean? is there anything to it?

Hey friends, today I want to cover a topic which really caught my interest a few months ago.
I was watching another speech about nutrition and the impact your food has on your body when the doctor who gave that speech said something along the lines of „You become what eat, literally.“ Now, I have heard that saying a lot of times but that „literally“ was new to me. I have always thought that was just a saying to get to people to eat healthier.

But! I did my research afterward and found out a few very interesting things which I want to share with you guys today. So, if you want to find out why he said „literally“, bare with me, you won’t regret it!

Firstly, I was about to find out how our body processes food. I thought ​we eat food, it drops down to the stomach, the acid will break it down so our intestines can absorb the nutrients of the food and then shoot the leftovers down the john. It turned out to be true, so somewhere in there must happen the literal thing, right?

Secondly, I came across an article which claimed that our body replaces around 40 to 50 billion cells every day - WOW. That number was new to me, immediately caught my attention and I dug into it. Therefore, I searched for essays talking about cell reproduction and so on and so forth. It turned out that In total, estimates of cell turnover in an adult human is about 50-70 billion per day. Most that are not neutrophils are the epithelial mucosal cells that line our GI tract from mouth to anus. Divide 70 billion by 24 to get the number per hour, and divide that by 60 to get cells per minute. You've got to do some work, right?

But, aren’t there different types of cells in our body? Is every cell the same? Is every cell replaced each day? That would mean that every cell in our body has a lifespan of only 24 hours. The answer is no. Red blood cells live for about four months, while white blood cells live on average more than a year. Skin cells live about two or three weeks. Colon cells have it rough: They die off after about four days. Sperm cells have a lifespan​ of only about three days, while brain cells typically last an entire lifetime (neurons in the cerebral cortex, for example, are not replaced when they die - stay away from drugs people, these cells won’t come back).

Now, what does „literally“ mean here?

Every cell that is replaced in our body, uses the nutrients we provide it with to build itself.
Ahh, there we go. It makes more and more sense, ​doesn’t it? If our body uses the nutrients of the food we eat to build new cells, we really „literally“ are what we eat. I would rather say, we become what we eat, instead of are what we eat though. Because this process needs some time, right?

Suddenly, all kind of imaginations popped up in my head and I got remembered of someone saying to me, if you eat that cheeseburger, you will become a cheeseburger. I was like what the heck are you talking about? You must be tripping. But, in fact, he was kind of right!

When I started to realize that you „literally“ become what you eat, I asked myself, do I want to become a cheap, fast and fatty cheeseburger​r?

Lastly, I want to leave you with this picture and as always encourage everybody to do his own research.

Cheers,
Daniel