After (semi) lecturing a client about why it was important to lose body fat BUT maintain (and gain) all the lean muscle she could - even if the “weight” on her scale didn't go down as quickly as she may have liked - she looked me straight in the eye and said:
"So...your whole process is just about building a better metabolism?”
I wanted to hug her. “YES,” I cried to my dear and startled client, “YES IT IS!”
And herein lies one of the most obvious but most misunderstood connections between exercise, body composition, and nutrition: metabolism. Scientifically, metabolism is the sum of all the chemical processes inside our body that help us maintain life. In layman’s terms, metabolism is the way in which your body converts and uses energy for fuel.
But how does this "metabolism" stuff matter to those of us out here in the streets, just trying to lose a little weight and feel great?
Listen, there are lots of reasons.
Your basal metabolic rate (BMR) refers to the amount of calories your body burns at rest – and the higher your BMR, the less you have to do to actually burn the energy (read: food) you consume. The more efficient your body is at burning fat for energy, managing glucose, and building muscle, the "faster" your metabolism is running (to use the colloquial term).
People with a greater muscle-to-fat ratio have higher BMR, even if their weight is exactly the same as someone with more fat than muscle. And people who are UNDERmuscled are at much higher risk for insulin resistance (the precursor to diabetes), which is often what people are experiencing when they think they have a "slow" metabolism.
(Also, to debunk a related metabolism myth, there is no such thing as "starvation mode" or "undereating" into a slower metabolism; calorie deficit is in fact the way that human bodies achieve weight loss across the board.)
In short: metabolism matters, and you definitely want yours firing on all cylinders. So what can you do to promote a healthier metabolic profile?
First and foremost – SLEEP! A lack of sleep (less than 7 hours for adults), particularly when chronic, can lead to a neuroendocrine imbalance that not only makes the body store more energy as fat, but can also make you feel ravenous all day long (increased ghrelin, the appetite hormone) and forget to tell you when you’re had enough to eat (decreased satiation regulators).
Second of all, lift weights. I’ve talked about this time and time again, but the single best thing you can do to “speed up” (and I use this term loosely since you don’t actually change the metabolism itself but rather its efficiency in processing energy) your metabolism is to build lean muscle. Every pound of muscle burns TRIPLE the amount of calories (six versus two) than the same weight in fat. If you want to burn more by doing less (something appealing even to my least-active client), muscle is where it’s at.
Third, eat food & drink water. Eating a diet rich in lean protein and fibre-rich vegetables is key to a healthy metabolism, but eating too often, too many carbohydrates/sugars, and too many calories will have the opposite effect. Protein is the best muscle-retaining macronutrient out there, fibre helps digestive and gut health stay intact, and staying hydrated (with water, by the way) makes all of your body’s most vital processes run smoothly and more efficiently.
Finally, be a mover (and heck, while you’re at it, a shaker). In addition to the muscle-boosting resistance exercise I mentioned above, what scientists are now calling NEAT (non-exercise activity thermogenesis) can actually be more effective in helping you lose weight. Everything from fidgeting to taking the stairs up to your office to standing instead of sitting to take a phone call counts as NEAT, and in very active individuals, their NEAT daily calorie burn is more than what most other people might burn in a 30-minute elliptical session (!).
The combination of what and how much you eat, when and how much you sleep, how much muscle you carry (and what exercises you do to get it), and your other lifestyle factors (stress, etc.) paints the majority of your metabolic picture. However, there are also factors outside of your control - genetics (womp womp), hormones (double womp), and certain medications - that will affect the way, and the rate, that your body holds onto and/or loses fat.
That said - when you harness the power of what you can do to improve your metabolic health, even those challenges can be reframed as catalysts to rise above what is outside your control and focus on what is within it - the ability to choose nourishing food, move your body regularly, and cultivate a positive mindset about what is truly possible in your wellness life.