Beware of n=1

Posted on December 18, 2012

(Last Updated On: April 11, 2016)

n equals 1

When a study or survey is done, n refers to the sample size -the number of subjects in the study. So if you survey 1000 people, n=1000.

In statistics and research, typically the greater the sample size the better. Because the greater the sample size the closer you get to studying the entire population you’re trying to look at.

This goes both ways though. The smaller the sample size the worse. Because the smaller the sample size the further away you get from studying the entire population.

Therefore, the greater the sample size the closer we can get to 100% confidence. The smaller our sample size, the less precise our study, or statements from that study are. In the latter we have to hope our sample size is representative of the entire population.

Let’s apply this to weight-loss. Say we’re dealing with the American population, roughly 330 million people.

You now understand – from a mathematical perspective – why anytime someone tries to justify a position to you with “I did this,” or “My friend did this,” you should be highly skeptical. Why? Because n, their sample size, = 1. In other words, who cares what 1 out of 330,000,000 did?

Oh, this is common sense you say? Then why, when a person says:

-“I lost X amount of weight by only eating soup.” (Who eats soup?)

-“I lost X amount of weight by not eating carbs.”

-“I lost X amount of weight by not eating fat.”

-“I lost X amount of weight by eating more fat.”

-“I lost X amount of weight once I added [hocus pocus] supplement.”

-“I cured my breast cancer by eating Paleo, bro.”

-“I made my penis an inch bigger by eating grass fed beef.”


Something else to consider is, when n=1, all you’re being told is what worked for one person. What you’re not being told is how many people did that method not work for. It may have worked for the first person then failed with the next 99. That would be a poor approach.

Studies themselves fit into this as well. Perhaps one study says something, but 15 others contradict it. Eventually you have to conclude the first study either had something go awfully wrong, or is an outlier.

People and clients always ask me “Well, what / how do you eat?” And I always respond “You can’t use me as your example.”

-Do you have an immensely active job? 8-10 hours worth of such a day?

-Are you 6’4″?

-Do you deal with health for a living?

-Are you single, with no kids, and barely any responsibility except chasing after girls?

-Do you have the alcohol tolerance of a rhinoceros?

Then you shouldn’t worry about what works for me. What you should worry about is what works for most people, and then what can you take from this information to make it work best for you.

Yes, I realize I just wrote a post detailing how you aren’t unique, but after those certain truisms are met a great deal of variance can occur. Again, the mistake here is thinking you; only you, have some rare trait that absolves you from meeting criteria many other people have to meet too.

In the context of this post, the mistake is going to the other extreme- where you construct all your beliefs based on one study or person, a person who likely has many differences than you, and then using these beliefs to fuel your own behavior.

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