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Mad Positivity | Your Body is not a bank account
By Jessica Vander Zaag
“Gonna do some extra cardio cause I’m going out for ice cream after this”
“You’ve earned some dessert after that workout”
“Ugh I ate so much this weekend, I have to hit the gym every day this week”
Now I know we’ve all heard these sorts of statements before, heck they’re posted on the gym’s social media from time to time. Because we like to believe in the calories in/calories out model, that says you consume X calories in food and burn Y calories with activity, and that if X is greater than Y you gain weight and if X is less than Y you lose weight. Simple.
In principle this is correct, I won’t deny that, but there are significant limitations. Remember back when I called our bodies “wonderfully complex meat sacs”? Cool. Let’s dive into that.
Often when we think “burning calories” what comes to mind is exercise, but our bodies mostly use energy just to keep us alive. For starters there’s the Basal Metabolic Rate, or BMR, which I like to describe as the energy it takes for your body to maintain homeostasis if you were in a coma. You’re welcome to go look up the number if you’re a numbers person (though I caution that the accuracy is pretty limited with any of these generalized equations) because I would bet its higher than you were expecting. Now considering that everyone is awake and reading this we get into NEAT, or Non-Exercise Activity Thermogenesis. This includes the energy your muscles are using to keep you sitting upright and scrolling down this article, the energy your brain needs to be able to read, the energy your digestive system is using to break down lunch. All of the things our body does in an average day that we just consider living, take energy. And then last of all we have the exercise we know and love.
Now you’re right, you can control exercise, so let’s consider an example. You eat a cookie that has 100 calories in it, walk in to the gym, hop on the rower, and pull for 200 cal. Basic arithmetic says that now you will now lose weight.
But what happens when you get home?
Your body is a good budgeter. It will react to this high energy expenditure by sending signals that you need to consume more energy- the ravenous post-workout hunger we all know and love- and it will cut metabolic costs where it can. This is in easily perceptible ways like your energy levels: after putting in a big session at the gym do you go play outside or plop down on the couch? It will also save in ways you might not notice. Without available energy muscle growth (aka all those sweet gains you’re working towards) won’t happen as your body will be forced to use its limited resources for more basic functions.
Keep up a significant calorie deficit for long enough and your BMR will start to drop too. An extreme example of this that has allowed for some really interesting research is the “Biggest Loser” competitions. Scientists found that the Basal Metabolic rate of participants dropped disproportionately to the amount of weight that they lost. That is to say, while you would expect someone with less mass to require less energy, these individuals required even less than was calculated for their lower size. [https://onlinelibrary.wiley.com/doi/full/10.1002/oby.21538]
Now what’s my point?
It’s not impossible to make lifestyles changes and see your body react, but it does happen in far more complex ways than we give it credit.
To reduce fitness to a means to barter with your food choices is like telling your kid they can’t have dessert until they eat their broccoli. Yeah they should eat it, but they should eat it because it’s good for them, not as payment for a reward. Plus every parent knows the best way to get a child to eat veggies is to serve them in a dish they actually enjoy eating.
The equation is still simple: eat what you want to eat when you want to eat it, exercise in ways that bring you joy, and let your body do the rest