I’m currently participating in an Accountability Group on Facebook, “The Master’s Challenge” with over 33,000 people. We are all following Beachbody’s new program The Master Hammer and Chisel. We just started week seven out of eight and an interesting topic keeps coming up in the group…”I’m exercising more, eating less, so why haven’t I lost more weight?? Is my metabolism broken?!”
I get it, really who doesn’t want to lose fat and gain muscle? The problem with assuming that the metabolism is broken doesn’t play the long game. It also leads to crash dieting.
The Master Hammer and Chisel uses Autumn Calabrese’s container system approach to eating (primary focus of her 21 Day Fix program) which doesn’t work on counting calories (a good thing) but rather has differing sized and colored containers for the different food categories, i.e. green container for veggies, etc. You would pick a calorie bracket and it would have a certain number of food containers you are able to eat each day. Basically it provides a great visual for learning portion control. Here is a four minute video of Autumn giving a high-level overview of the eating plan (https://youtu.be/dyu1OxivVzg).
Even with a visual portion control system, a bunch of the participants continue to have similar results…that despite working out six days per week doing a blend of intense cardio and resistance, plus eating carefully, they’re not losing weight (or not losing it as fast as they’d like or expect).
Maybe you have had a similar experience and start to wonder “Is my metabolism damaged?” Or maybe you think you need to further lower your calories.
Do months or years of dieting cause some kind of long-term harm to how your body processes food?
Not the way you think.
Rather gaining and losing fat can change the way your brain regulates your body weight.
In Part One we will go down the rabbit hole of how your metabolism works and if it gets damaged.
Understanding Energy balance: Ugh, physics
Energy keeps you alive, allows you to move, and it comes from calories. This energy comes from food you eat or that your body has stored, i.e. fat.
This is where the idea of eating less energy than you use will cause you to lose weight.
The connection between ‘energy in’ and ‘energy out’ gives us the Energy Balance Equation. This is the go-to model for calculating a person’s energy balance and how much weight they’ll lose or gain over time.
The problem is it doesn’t factor in body composition which is influenced by things like sex hormone levels, macronutrient intake (especially protein), exercise style / frequency / intensity, age, medication use, genetic predisposition, and more.
Obviously, the Energy Balance Equation doesn’t usually give us the results we are looking for because of the other variables.
Caveat: “Eat less, move more” generally is a good starting point… Seriously you and I could probably benefit from eating a little less and increasing our daily activity.
So, let’s add in a few of those factors to better understand our metabolism, starting with
Your food label is lying to you. The calories can be off up to 25%.
We don’t always absorb, store, and/or use all the calories from food. Your body digests and processes differently than mine for a ton of reasons (like enzymes, gut biome, etc.)
Sidebar: You will absorb fewer calories from minimally processed carbohydrates, and fats, because they’re harder to digest.
Flip that around and you will absorb more calories from highly processed carbohydrates and fats, because they’re easier to digest. Basically, the digestion is already done for you.
Tip: If you focus on eating a diet rich in whole, minimally processed foods, the number of calories you absorb can be significantly less than what you expect. Bonus, those foods also require more calories to digest.
Tip: Avoid highly processed foods because they are less filling, more energy dense, and more likely to cause overeating.
The side of the equation of “energy out” varies by individual because of a number of variables at play, but generally falls into four categories.
The four key parts to this complex system:
- Resting metabolic rate (RMR)
- Thermic effect of eating (TEE)
- Physical activity (PA)
- Non-exercise activity thermogenesis (NEAT)
First, RMR is the number of calories you burn each day at rest, just to breathe, think, and live. RMR makes up about 60 percent of your ‘energy out’ and varies due to weight, body composition, sex, age, genetic predisposition.
A bigger body, in general, has a higher RMR.
Second, Thermic effect of eating is the energy it takes to digest food. Yup, digestion is an active metabolic process or the calories you burn through processing your food and is about 5-10 percent of the energy out.
Tip: Eat protein because you’ll burn more calories in your effort to digest and absorb protein (20-30 percent of its calories) compared to carbs (5-6 percent) or fats (3 percent).
Third, Physical Activity are the calories you burn from purposeful exercise, such as walking, running, going to the gym, gardening, riding a bike, etc.
This is generally the part of the energy out equation that most people focus on.
Finally, Non-exercise activity thermogenesis represents the calories you burn through fidgeting, staying upright, and all other physical activities except purposeful exercise.
So ignore what your teacher used to say and fidget away…
Here’s the rub
Your body likes homeostasis, so when you adjust one variable in the Energy Balance Equation, than your body adjusts variables on the other side.
For instance when ‘energy in’ goes down, ‘energy out’ goes down to match it which means you burn fewer calories in because you ate less.
Yes, yes, it doesn’t hold true for everybody, but remember your body treats weight loss like starvation.
For example, when you consume fewer calories your body may respond in any of the following ways:
- Thermic effect of eating goes down because you’re eating less.
- Resting metabolic rate goes down because you weigh less.
- Calories burned through Physical activity go down since you weigh less.
- Non-exercise activity thermogenesis goes down as you eat less.
- Calories not absorbed goes down and you absorb more of what you eat.
- Hunger signals to increase, causing us to crave and possibly eat more.
When these responses occur it may lead to a lower rate of weight loss than you might expect. Even worse, it could even lead to weight re-gain.
And salt in the wound, a rise in cortisol from the stress of dieting can cause our bodies to hold onto more water, making us feel “softer” and “less lean” than we actually are.
In the end, these are just two of the many examples we could share. The point is that metabolism is much more complicated (and interdependent) than most people think.
Now you’ve seen a glimpse into how complicated metabolism is and with a better understanding of energy balance allows you to set a better expectation about body change.
Back to the original question…
Does dieting damage the metabolism?
No, losing weight won’t “damage” your metabolism.
However, losing weight (and keeping it off) creates adaptive metabolic, neuroendocrine, autonomic, and other changes.
The changes then mean you will use less energy, like around 5-10 percent less than what would be predicted based on just weighing less.
The further complication is that someone who has dieted down will often require 5-15 percent fewer calories per day to maintain the weight and physical activity level than someone who has always been that weight.
What does that mean? Basically, someone who was never overweight might need 2,500 calories to maintain their weight, while someone who had to diet down to that weight may need only 2,125-2,375 calories to hold steady.
This is especially important if you are a yo-yo dieter because this adaptive thermogenesis seems to react more strongly or more rapidly with each successive yo-yo of extreme body fat fluctuations.
This can help explain why some people feel like they’ve “damaged” their metabolism through repeated dieting.
Just know that you aren’t “damaged”.
Rather, your body may have just become more sensitive to various hormones and neurotransmitters.
Where do we go from here?
Yes, you guessed it…body change will be easier for some and harder for others…all physiological changes as in weight loss/gain, fat loss/gain, and muscle loss/gain.
However: even if your body might defend against weight loss, you can still lose weight, gain muscle, and dramatically change your body!
Questions for you: Do you feel like you are metabolically damaged? What programs have you tried and which ones have had the best results?
To your success!