What Is an N-of-1 Experiment?

Do you have what it takes to be a biohacker? Self-experimentation can help you find what works for you - and might help scientists too! Nutrition Diva reports on the latest in diet data.

Monica Reinagel, MS, LD/N, CNS
5-minute read
Episode #321

When researchers write about studies, the number of subjects in the study is often described as “n = 24” or “n = 500” or however many people the study involved. The bigger the “n,” the more confidence you can have in the results.

Researchers will often do a pilot study using a very small “n,” because it’s a lot cheaper. If the results of a small study are promising, they can then invest in a larger trial to test and strengthen their findings.

So, an n-of-1 experiment is the smallest study you could possibly do: one that involves just a single subject. Lately, the term has become a bit of a buzzword with so-called “biohackers,” folks who like to experiment with different diet or lifestyle regimens to see what works best. 

See also: How to Biohack Fat Loss With a Kettlebell


Are N-of-1 Experiments Valid?

How valid are n-of-1 experiments? Well, they aren't very helpful in predicting how someone else might respond to the same regimen. In order to do that, you'd need to test your intervention on lots of people. Some of those folks will have positive results, some will have negative results, and some will have no result whatsoever. The percentage of people who have a certain result suggests how likely it is that another person would have that same outcome.  

Why is it all so fuzzy? Because each of us is so different. We have different genes, different health histories, different lifestyles, and different environments. No matter how hard we try to control the variables, we will never all respond the same way. 

But if all you really care about is how YOU respond to a given workout or diet, then an n-of-1 experiment is all you need.

Why You Should Do an N-of-1 Experiment

Although I usually don’t refer to them as n-of-1 experiments, I actually suggest them to you all the time. There are a lot of dietary theories out there—based on ideas that haven’t been definitely proven but haven’t been disproven either.

For example, some people believe that grains are bad for you. Others are convinced that dairy products aren’t healthy for human beings. Some think that our ideal diet is determined by our blood type. And so on.

Some of these theories are more convincing than others. Often, there is a lot of contradictory research that makes it hard to say one way or the other. But as long as a dietary approach isn’t dangerous, I see no harm in experimenting. If you feel or function better when you eliminate dairy or grains or meat or whatever, and you can maintain a balanced nutritious diet without that food, then I’m all for it.

I don’t think, however, that this means that everyone must adopt that same diet, or even that your success necessarily “proves” that your theory is correct.

See also: How to Create Your Own Best Diet



About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.