As I have written about quite a bit lately on this website, I am currently on a calorie-deficit diet. This diet is tricky because I want to lose most of my body’s stored fat but not my muscle mass. In an interview that I watched with legendary bodybuilder Mike Mentzer, he mentioned that he would never go below 1,500 calories a day when he was running a deficit because below that number his body would start to metabolize his muscle mass.
Mentzer was larger than I am, so I personally try to stick between 1,500 to 1,600 calories per day and trust that it is enough to ensure that I won’t lose muscle mass. My daily ‘maintenance calorie level’ according to a reliable calculator is roughly 2,700 calories per day for reference. Most studies and testimonials that I have come across indicate that a person needs to run a deficit of at least 500 calories per day to make meaningful strides in weight loss.
A question that I have been asked lately in real life, and have seen posed quite often on social media, hinges on which one is easier – building muscle or losing fat? Ultimately, people should strive for both if they are overweight. The two are not necessarily mutually exclusive.
With that being said, building muscle is much more difficult to do from a time perspective. For context, I was able to lose 13 pounds of stored fat in the last 6 weeks by being on a disciplined calorie deficit diet, and that’s virtually impossible to do in the opposite direction for building muscle mass. I leave the possibility open that if the right person was roided to the gills, which I am not, perhaps they could hypothetically gain 13 pounds of raw muscle in six weeks, but even then, the research doesn’t seem to back that up.
The fact of the matter is that it takes quite a bit of time, adhering to a protein-rich diet, and a lot of weightlifting to build a person’s muscle mass. And while it also takes time to lose stored body fat, if a person is truly disciplined, they can lose fat faster than they can build muscle. Which is why even while I am on a calorie deficit diet, I value my added muscle mass more than losing my stored body fat.
I was recently asked how I know if, despite being on a calorie deficit diet, whether or not my body is metabolizing my muscle for fuel. For starters, I do visual checks every day, and while my midsection is getting slimmer due to reduced stored fat, my upper and lower body muscles are the same size, albeit with a bit more definition. I also have either maintained my strength level in the gym on certain lifts over the last six weeks, or even gone up a smidge on some of them.
I attribute my maintained muscle mass to not going below 1,500 calories per day, and making sure to consume at least one gram of protein a day for every pound that I weigh. If I have to err on one side of the equation, muscle will always win, especially since I am middle-aged and building muscle mass gets harder as humans get older.
“As the years pass, muscle mass in the body generally shrinks, and strength and power decline. The process begins earlier than you might think. Sarcopenia—defined as age-related muscle loss—can begin at around age 35 and occurs at a rate of 1-2 percent a year for the typical person.” Harvard Medical School stated in a recent email that I received. “After age 60, it can accelerate to 3 percent a year. The loss may be mild, moderate, or severe—or muscles can remain in the normal range.”
“On average, adults who don’t do regular strength training can expect to lose 4 to 6 pounds of muscle per decade.” Harvard stated in their email blast. “Fast-twitch fibers, which provide bursts of power, are lost at a greater rate than slow-twitch fibers, which means you’re not only growing weaker but also getting slower.”
I get that people want to lose fat, especially this time of year with ‘beach season’ on the horizon. I am one of those people. Just make sure to do it in a responsible way so that it doesn’t come at the expense of your added muscle (or your overall health).
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