One of the common comments people make about weight control is: “It’s just calories in / calories out.” It’s true, but it’s also wrong in important ways.
For example, one of the things that we know happens once people reach their thirties is that they start to lose 3-5% of their muscle mass per decade. In medical terms, this process is called “sarcopenia with aging”, and it accelerates further when most people reach their seventies.
So, “sarcopenia with aging” is slowly reducing “calories out” for most people older than 30, and this subtly shifts the equation of “calories in / calories out” over time. It’s a force that requires that we either:
- Consciously change our eating habits to reduce calorie intake as we age
- Work to reduce sarcopenia through a program of strength training
But, doesn’t the human body’s homeostatic mechanisms guide us to reduce intake as we burn fewer calories? Yes, it does. Except we live in a cultural environment that makes every effort to disconnect eating from feelings of hunger. Make sure to eat three square meals a day is an idea that puts food consumption on a predictable schedule. From there, the concept has evolved further, where food has become primarily a recreation for many people.
Consider the ever expanding “holiday” and spectacle seasons. Is it a coincidence that the Super Bowl (or pick your holiday/spectacle of choice) party is an excuse to eat and drink in ways that make weight control difficult, if not impossible?
The same dynamic is in play with ever increasing portion sizes and richer, more calorie dense food. Movie theaters sell large tubs of popcorn, soda and candy to justify increased prices, which offset decreased ticket sales. Whether you are talking about eating out in restaurants or convenience food, there are billions of dollars being spent delivering just one message: “Eat more.”
Why? Imagine if everyone in the United States cut their calorie intake by 100 calories a day, how many billions of dollars of revenue would that cost food companies in a year? Conversely, the opposite is also true. More calories equals more revenue.
In the context of this dynamic, the “calories in / calories out” argument is problematic. On one level, it suggests that weight is an individual problem. It is as if the billions spent on food marketing, the dearth of sound nutritional advice available to most people, the socio-economic constraints of food availability, etc. are all irrelevant. On another level, the idea of an “equation” implies that “calories out” is a viable approach to a weight problem, and it is why exercise is so often offered as a solution.
But, the treadmill, the elliptical machine, the stationary bike, the aerobics class or other cardio exercise is not how you address the problem of “sarcopenia with aging”. And cardio exercise, by itself, is not enough. There is a saying, “You cannot outrun a bad diet.” Unless you are someone like an elite endurance athlete logging +100 miles of running a week, the only way to bring weight under control is to eat less, not more. Exercise can be an important catalyst for changes, making them happen faster. But, exercise can also undermine weight control as it drives increased appetite and can make it more difficult to eat less.
We need to eat less in an environment where we are always incentivized to eat more. Saying “it’s just calories in / calories out,” is like saying, “Just eat less.” It’s correct, but it’s missing taking into account many of the factors that make that so hard.