Choose your obesity research source on the Internet (sciencebasedmedicine.org, mayoclinic.org, healthline.com, etc.), and you will commonly be told that if the number of calories taken in are greater than the number of calories burned (through basic metabolism, digestion, and physical activity, etc.), you will gain weight.
Technically, this is true. In order to lose weight, you must have a calorie deficit. People who are starving lose weight. But if you’ve tried to lose weight by counting calories, you probably have realized that is not the whole story.
Before examining the calories in vs. calories out equation more closely, let’s look at a few of the facts about obesity.
In the 1960’s and 1970’s only 13% of U.S. adults and 5 to 7 % of U.S. children were obese. In its May 28, 2014 publication, healthdata.org states: “160 million Americans; nearly 75% of American men and more than 60% of women are obese or overweight while nearly 30% of boys and girls under age 20 are either obese or overweight."
From this information alone we can conclude that in the last 50 years something in our environment has drastically changed. Those changes have put the health of millions of Americans at risk.
Before looking at the idea of counting calories, some other facts should be considered:
- As of 2014 the average American ate 3770 calories/day. (The 2019 calorie average/day is probably higher.)
- The average man needs to eat 2500 calories/day and the average woman needs to eat 2000 calories/day to maintain a constant weight.
- One pound of body fat equals approximately 3500 calories.
- If the biological chemistry of weight control could be reduced to the mathematical formula of [calories in = calories out] (also referred to as CI = CO, or CICO), to lose one pound/week, the average man would have to reduce calorie intake to 2000 calories/day and the average woman would have to reduce calorie intake to 1500 calories/day.
- Although the mathematical formula of CICO [Calories In = Calories Out] sounds plausible and is conventional wisdom, the biology of the human body is more complicated than a simple mathematical formula.
- Both the food eaten, and the social customs of the average American have changed drastically since the 1960’s and 1970’s.
- There is no easy way to count actual calories eaten per day.
- It is even more difficult to count actual calories burned per day.
- Most Americans consistently underestimate the amount of food they eat daily.
- Calories per serving on food packages are given in serving sizes that are not equal the amount most people eat.
- Calories on food packages are not guaranteed to be accurate and can be off by at least 10%, and
- If the average American is 30 to 50 pounds overweight, wants to lose that amount, and CICO does work, that person would have to cut what they eat in half for 8 months to a year.
In my next post, I’ll examine some of the math that would need to work if CICO [Calories In = Calories Out] could be used for weight control and why this approach commonly fails.