I can't seem to lose weight. I'm "skinny fat." I can't build muscle mass. I feel like I'm spinning my wheels.
I hear some version of this constantly. And before I give anyone advice, I think there are two questions worth asking yourself: Where do you stand metabolically? And what steps are needed to restore it?
Most people can't answer either one, because nobody ever explained the machine to them. So before we get to what to do, I want to lay out a few concepts. How you react to these will tell you a lot about where your understanding actually is.
You breathe it out
Have you ever wondered where your "weight" goes when you lose it? You breathe it out. Literally. Exhaled CO2 can amount to pounds of body fat over time. In a typical 24-hour period, a person exhales roughly a kilogram of mass as carbon dioxide.
One caveat that makes this meaningful rather than just a fun fact: most of the carbon you exhale on a given day came from the food you ate that day. It's passing through, not coming out of storage. It's only the portion you're running at a deficit that gets pulled from your fat stores and exhaled. Which is exactly why this is such a slow process — and why I'll keep coming back to that.
What a pound of fat actually costs
If you wanted to lose 10 lbs of body fat, how many calories would that be? Roughly 35,000. To put that in perspective, you'd need to run somewhere in the range of 350 to 400 miles to burn that many calories.
Sit with that number for a second. Not because I want you to feel discouraged, but because it explains almost everything about why people fail. You are not going to exercise your way through 35,000 calories in a few weeks. Nobody is.
Most of what the scale reports is water
Our muscles and tissues store energy as glycogen, and those molecules are heavily hydrated — every gram of glycogen carries roughly three grams of water with it. Add in what's physically in your gut and the way your body holds sodium, and 5 lbs can ebb and flow depending on how many carbs you've eaten and how much water you've been drinking over any given few-day period.
So when the scale jumps four pounds after a weekend, essentially none of that is fat. And when it drops five pounds in your first week of a diet, essentially none of that is fat either.
There's a second thing worth knowing about glycogen: our muscles function better when they're properly fueled. The strategies that make the scale move fastest are often the ones that leave you least able to do the training that actually changes your body.
The point
At the end of the day, our physical bodies are biological machines that take in fuel, use it, and store it. Understanding how all of this works is essential for those of us trying to rebalance or restore our metabolic function.
And it reframes the goal. In most cases what we actually want is either to become leaner — to reduce our body fat percentage — or to build lean body mass. "Losing weight" is unclear, and you might not become healthier at all if the weight you lose is lean body mass, especially muscle.
You can lose weight and end up worse off. That happens all the time, and it's the subject of the next piece.
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