A brief look at the relationship between energy usage and obesity

Posted on June 29, 2016


Using the CDC, we can see the obesity rate for each state in 2014.

Using the U.S. Energy Information Administration we can see how much energy each state used for 2013.

Using 2010 census data we can see the population of each state.

If we divide the energy use per state by the amount of people per state, we get the average amount of energy used per person for that state. (We don’t want to only look at total energy use per state, as some states have way more people than others.)

If we put this into a spreadsheet, using Excel’s correlation function, we can see the correlation between energy used per state, and how obese that state is. We can also put this in graphical form:

Energy use per state vs obesity rate per state

The correlation between the two comes out as 0.38.

Correlation wise, the number can be between -1 to 1. Positive being a positive relationship (they go up together); negative being a negative relationship.

  • 0.7 to 1 is considered a strong correlation
  • 0.5 to 0.69 is considered moderate
  • 0.3 to 0.49 is considered weak
  • 0 to 0.3 is considered not worth considering
  • None say anything about causation. Just that they’re related for some reason.

Our 0.38 would mean there is a weak relationship between the amount of energy the individuals in a state use, and how obese they are.

To check the data, I also entered in numbers for the percentage of each state with a bachelor’s degree. That number came out to -0.75. Meaning as educational attainment goes up, obesity goes down. That’s in line with heavier research, so these numbers make sense so far.

However, eye balling this chart, it’s pretty apparent we have four outliers.

Energy use per state vs obesity rate per state with outlier circle

Going back into the data, these outlier states are:

  • Alaska
  • Louisiana
  • North Dakota
  • Wyoming

(Using an outlier calculator, the numbers for these states were indeed outliers.)

Now why these states use so much energy per person compared to others, well being that I’m from New Jersey and live in California, and have traveled a good deal of the States, I’m going to say “Those places are weird,” and leave it at that.

-> Seriously, California used a total energy of 7,684 trillion btu. Louisiana, with only ~4 million people to California’s ~37 million, used 3,838 trillion btu. Nine times less people, yet only half the energy usage? Louisiana and Kentucky have essentially the same population size, yet Kentucky uses less than half the energy of Louisiana. What the eff?

If we remove these four states:

Energy use per state vs obesity rate per state 2

That looks a bit cleaner, and our correlation goes all the way up to 0.61. A solidly moderate relationship between the two.

The point

Humans have an innate desire to decrease the amount of energy they expend. The primary way we’ve accomplished this the last couple hundred years is by getting other things -machines- to expend energy for us.

Since this time, we’ve gained more and more weight. From 1910 to 1970, people had nearly a 20% decrease in the amount of active jobs they partook in, and not coincidentally, people got heavier. It’s worth stating though that since our obesity rates started soaring, also ~1970, more of the blame is on how we eat.

Part of the potential explanation for not seeing an even stronger relationship between our activity levels the last few decades and increasing obesity rates is most research can’t even measure the lengths we’ve gone to decrease our energy output. Most of the time the research is survey, asking people what they do for work, or what they do for recreation. It’s not measuring how much less you have to click a mouse each day. It’s not measuring how much less your brain has to work each day due to Google. How I can’t judge people based on their grammar anymore because of autocorrect. How you don’t have turn your head to see what’s behind you when driving. It doesn’t measure how you can instant message someone rather than walk down the hall. It doesn’t measure to change the TV channel you can press a button rather than stand up to switch the dial. That making dinner may consist of pressing the microwave button rather than being on your feet cooking for 45 minutes. That social interaction can consist of FaceTime rather than going and meeting someone. To clean your floor you can press the button of a robot rather than sweep with your limbs.

This is real- I could

  • wake up, in bed, and start working on my laptop,
  • get up, onto a hoverboard and hover roll to my electronic toothbrush which basically brushes my teeth for me,
  • roll to get my meal from the button I pushed to heat it up,
  • roll over to my front door and get the razor which was delivered to me, plug it in and move my hand a few times to shave,
  • roll out my door to my apartment’s elevator,
  • look at the screen going over the weather and news (heaven forbid I be alone with my thoughts for 25 seconds)
  • roll into the Uber I took three finger presses to order,
  • listen to the maps app direct the driver so I nor they have to remember the way to the airport,
  • (I already know my flight is on time and what gate to go to because it was texted to me)
  • roll to baggage check with the bag that’s been rolling behind me; roll the bag onto the scale,
  • roll to security,
    • yes, pretty much all airlines just banned hoverboards, but that’s likely to be resolved as more reputable and better manufacturers hit the market.
  • use my fingerprint to unlock my phone rather than have to press a button,
  • turn my hand to show the boarding pass which was emailed to me,
  • lift my hands to get scanned by a machine rather than a person needing to move their hands,
  • continue my rolling to the escalator which brings me up a floor,
  • continue on the airport’s moving walkway so I get a break from leaning forward on my hoverboard,
  • get on a plane and go across the country while a screen talks to me so I don’t need to talk to someone next to me,
  • roll to baggage claim and grab my bag which was brought to me,
  • roll out the airport,
  • get in another Uber,
  • elevator to my hotel room,
  • eat the food which was delivered to me,
  • take some pills so I don’t need to chew vegetables,
  • back in a Lyft as Uber was busy,
  • get on the Segway tour of the new city I’m in.

You can travel across the world barely moving a limb or even needing to open your mouth. That’s extraordinary!

So the question is, should we keep doing this? Because this is also extraordinary: there are now more obese people in the world than underweight people. 40% of women (and 37% of men) are now obese. Nearly every other woman you see is obese! Whatever your job is, are you decreasing the amount of energy someone expends each day (meaning something else is expending that energy)? Should you be?

There are people who want to take this further. Like at least I still need to take a few minutes to buy the airplane ticket, even if Kayak sorts through all the prices for me. But there are people who want to make it so I can text or say to my phone “Buy me a ticket to such and such.” Five minutes of effort down to five seconds. Rather than me having to look up on Yelp what some of the better reviewed restaurants are (opposed to walking around, asking people and checking out menus) and get a reservation myself, people are trying to make it so I can text or say to my phone “Get a reservation at a restaurant I’ll love.” They even want this digital assistant to pick which item on the menu you’ll like best.

You may think, “But that’s how the economy works. I make someone’s life easier / more convenient / less metabolically costly, and they pay me money. At least that’s how the overwhelming majority of the economy works.” In which case we may need to consider two possibilities:

  1. Is the way the economy is currently structured at odds with public health?
    1. Hell, is the way the economy is currently structured at odds with the economy? When nearly a fifth of your spending has to go to healthcare, that hits the rest of the economy hard.
  2. Is human nature currently at odds with human health?

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