How much energy could we save if no one was overweight?

Posted on March 23, 2016


(Last Updated On: February 7, 2018)

Solar, electric cars, we’re waiting for these and others, these so called energy fixes, to get cheaper so we can all have them. There are two billion cars on the road in the world. 100 million cars are made each year. If every single car produced *today* was electric, it would take 20 years to refill the fleet. Electric cars currently make up less than 1% of auto sales.  How many alive today will even see these “solutions” in full effect in their lifetime?

Is there anything else we can do? Things with theoretically no time constraints? Food, that is, calories, are energy. Extra calories on people’s bodies is extra…wasted…energy. What if that didn’t exist?

In America,

  • More than 2 in 3 adults are considered to be overweight or obese.
  • More than 1 in 3 adults are considered to be obese. (So we’ll say 1/3 obese, 1/3 overweight.)
  • More than 1 in 20 adults are considered to have extreme obesity.
  • About one-third of children and adolescents ages 6 to 19 are considered to be overweight or obese.
  • More than 1 in 6 children and adolescents ages 6 to 19 are considered to be obese.

There are,

  • 319 million people in America
    • ~76%, 244.8 million, are above 18
    • ~24%, 74.2 million, are under 18
  • 244.8 million adults
    • 1/3 obese = 81 million
    • 1/3 overweight = 81 million
  • 74.2 million non-adults
    • 1/6 obese = 12.33 million
    • 1/3 overweight or obese = 24.5 million overweight or obese – 12.33 million obese = 12.16 million overweight

How many calories do these people require? Body Mass Index is commonly used to assess overweight or obese.

  • 25 to 29 is overweight
  • 30 and up is obese

Extreme obesity is classified at a BMI of 40 and over.

BMI = (bodyweight in kilograms) / (height in meters^2)

We’ll say the median overweight person has a BMI in the middle, 27.5, and the median obese person has a BMI of 35. So we’ll say half of obese are lower than 35; half are higher.

Average U.S. adult height is 5’6″ or 1.68 meters.

Overweight people:

27.5 = bodyweight / (1.68^2)

(1.68^2) * 27.5 = 78 kilograms

The average overweight person in America has a bodyweight of 78 kilograms. 171 pounds.

Obese people:

35 = bodyweight / (1.68^2)

(1.68^2) * 35 = 99 kilograms.

The average obese person in America has a bodyweight of 99 kilograms. 217 pounds.

With children it’s a bit harder. The data is for children 6 to 19 years of age. We’ll take the average height of a 13 year old, which seems about 5’1.5″ or 1.56 meters.

Overweight children:

27.5 = bodyweight / (1.56^2)

(1.56^2) * 27.5 = 67 kilograms

The average overweight child in America has a bodyweight of 67 kilograms. 147 pounds.

Obese children:

35 = bodyweight / (1.56^2)

(1.56^2) * 35 = 85 kilograms

The average obese child in America has a bodyweight of 85 kilograms. 187 pounds.

Life expectancy in America is 79 years. We’ll say the average age of an adult in America is halfway between 18 and 79, or 49 years old.

For children, we’ll use halfway between 6 and 19, or 13.

Using a random calculator to figure out how many calories these weights burn per dayusing the heights above, the ages above (how much we burn can change (decrease) with age), averaging between males and females, assuming these are sedentary people,

5’6″, 49 years old, adults:

  • 171 pound overweight = 1869 calories per day
  • 217 pound obese = 2161 calories per day

5’1.5″, 13 years old, child:

  • 147 pound overweight = 1924 calories per day
  • 187 pound obese =2177 calories per day

-> It’s interesting to note here overweight and obese children burn more calories per day than overweight and obese adults.

Let’s say we could wave a magic wand and get all these people with weight to lose, down to a BMI of 22.5, right in the middle of what we consider the healthiest BMI range.

Adults:

22.5 = bodyweight / (1.68^2)

(1.68^2) * 22.5 = 64 kilograms or 141 pounds

Children

22.5 = bodyweight / (1.56^2)

(1.56^2) * 22.5 = 55 kilograms or 121 pounds

Using our same calculator and parameters but with these new weights,

  • Adults would burn 1679 calories
  • Children would burn 1758 calories per day

Therefore,

  • Adults
    • Overweight are burning 1869 – 1679 = 190 kcal
    • Obese are burning 2161 – 1679 = 482 kcal
  • Children
    • Overweight are burning 1924 – 1758 = 166 kcal
    • Obese are burning 2177 – 1758 = 419 kcal

All per day unnecessarily. This is wasted energy.

  • 81 million overweight adults * 190 calories per day = 15.39 billion calories per day
  • 81 million obese adults * 482 calories per day = 39 billion calories per day
  • 12.33 million overweight children * 166 calories per day = 2 billion calories per day
  • 12.16 million obese children * 419 calories per day = 5.1 billion calories per day

Totaling 61.5 billion calories per day not needed to be consumed.

  • 61.5 billion * 365 days per year = 22.4 trillion calories per year wasted

1 dietary calorie = 4134 joules.

  • 22.4 trillion calories = 9.37 * 10^16 joules

-> That’s 16 numbers after the decimal, for those unfamiliar with scientific notation.

The number jumps around a little, but agriculture usually comes in at about 16% of energy use in America. USDA says it was 12.2% in 1997, 14.4% in 2002, and 15.7% in 2007. 16% in 2016 seems fair.

Total energy use in the United States comes in around 9 * 10^19 joules.

  • (9 * 10^19) * 16% = 14.4 * 10^18 joules

 

Looking at our wasted calories relative to total agricultural energy,

  • (9.37 * 10^16) / (14.4 * 10^18) = 0.0065 or 0.65 percent.

But this doesn’t account for all the other ways food impacts energy. Travel, packaging, etc. It’s just calories. Perhaps a better way to view this then is what percentage of calories do people waste each day. Now we need to know the total amount of calories we consume each day. Using our calories numbers from earlier-

  • 82.8 million non-overweight / obese adults * 1679 calories = 139 billion calories
  • 81 million overweight adults * 1869 calories = 152 billion calories
  • 81 million obese adults * 2161 calories =175 billion calories
  • 49.7 million non-overweight / obese children * 1758 calories = 87 billion calories
  • 12.33 million overweight children * 1924 =24 billion calories
  • 12.16 million obese children * 2177 = 27 billion calories

Totaling 604 billion calories. We know from earlier we waste 61.5 billion each day.

  • 61.5 billion / 604 billion = 10.2%

So we’ll say we waste 10.2% of our agricultural energy strictly due to overeating.

 

Going back to energy use from agriculture in America, total energy use in the United States comes in around 9 * 10^19 joules, with ~16% dedicated to agriculture

  • (9 * 10^19) * 0.16 = 14.4 * 10^18 joules

We waste 10.2% of this number,

  • (14.4 * 10^18) * 0.102 = 1.47 * 10^18

This number as a percentage of total U.S. energy:

  • (1.73 * 10^18) / (9 * 10^19) = 1.6%

That’s an ok dent. Not sufficient in itself of course, but it’s something. Amazingly, we have other wasted calories we can address. Way more. It’s estimated we lose about 35% of our food to waste. Add that on top of the 10.2% we waste in excessive calorie consumption, and we are upwards of 50% of the calories we produce being wasted. That’s now 8% of the energy budget completely wasted. Just through food!

There is no law of nature dictating we couldn’t change our excessive consumption and waste overnight. It is theoretically possible to decrease our energy use by 8% now. “That’s not realistic” is only true in the what we can expect of humans sense. It’s not like we’re trying to defy a law of nature though. It’s not like we have to build the infrastructure to utilize other energy sources. Thinking back a few hundred years, how many were overweight and wasting food? Maybe it wasn’t zero percent, but it sure was a hell of a lot less than in the half of all food range. In one sense, we’ve done it before.

Solar, electric cars, we’re waiting for these and others, these so called energy fixes, to get cheaper so we can all have them. There are two billion cars on the road in the world. 100 million cars are made each year. If every single car produced *today* was electric, it would take 20 years to refill the fleet. Electric cars currently make up less than 1% of auto sales. Too many of us are waiting and relying on solutions most alive will likely not see in full effect in their lifetime. This is a time sensitive problem. Time is not on these solutions side. (They’re only partial solutions too.) It takes an inordinate amount of time to implement a new energy infrastructure. It takes an iota of time to use less energy.

Furthermore, unlike most energy use behavior, this would come at no cost to the population. On the contrary, people would lose weight, save money by eating less, save money by not buying as much food, the healthcare system would breathe the largest sigh of relief we’ve ever seen and use less energy, cancer rates would go down, airfares would go down as they are extremely sensitive to how much mass is on the plane (I have another post coming showing how much energy can be saved if flight passengers weren’t overweight), deforestation wouldn’t be as much, CO2 levels would be less.

If anything, these energy numbers are low ball estimates, as the ramifications of less food consumption / waste would reverberate throughout the economy. (It wouldn’t be much, but you’d get better gas mileage on your car too.) It is an endless list of benefits and a hard to find list of any consequences.

Most people who try or are trying to lose weight have a hard time. One way to potentially ease the process is by finding some motivation in that losing weight is not only about you. It’s about everyone, society, our ability to live on this planet. Often feeling like you’re part of something bigger than yourself provides fuel when things get tough. Sometimes a change in perspective, a change in mindset, as to why you’re doing something, can be your extra, figurative, fuel.

Update- Forgot to include non-overweight / obsese children in total calorie calculation

Jon Oliver and his team did a very good job covering food waste last year:

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.