I got 2 DEXA scans in 24h: 4.4lbs lean mass gained

In Soviet Russia, you measure DEXA scan?

computer generated: “dexa scan”

If you remember my posts about why I use a scale and my new, “upgraded” scale you’ll remember that I’m skeptical of the numbers stuff gives me. Just because there’s a decimal point doesn’t mean it’s true in a meaningful way.

So, of course, I had to measure the gold standard, the one and only - the DEXA scan. If you’ve never heard the term, DEXA stands for Dual-energy X-ray absorptiometry and is a machine that can measure the lean and fat mass in your body via x-rays. These are available, typically for $100 per scan or less, in many major cities. If you get one, make sure to ask for the body composition one, not the bone density one. Fun fact: the body composition results will also contain your bone density.

Many people consider the DEXA results the “real” number. I certainly like to verify my numbers with the DEXA scan and I think it can give you both a good baseline of fat mass/lean mass/body fat %, as well as tell you if you’re losing the wrong kind of mass (e.g. lean or muscle mass) over a few months.

But I was highly skeptical that the DEXA is actually less noisy than the scale. I suspected that the only reason people believed that is that nobody has a DEXA scan in their bathroom that they step on every morning.

Protocol: 24h protein refeed

My plan was to get a DEXA scan on the last day of a 30-day ex150 trial, and I chose ex150grassfed. Now maybe that wasn’t a totally perfect example, because I didn’t actually lose super much weight on that one, but I had to work with what I had. Also there certainly was a degree of lowered water retention and glycogen depletion, so it wasn’t the worst example either.

For the 24h after the DEXA scan, I’d stuff myself. But obviously not with junk food or candy, it would have to be food representative of what I normally eat off ex150: high protein, mostly beef, low seed oil (if any), some dark chocolate.

I had:

• 3 steaks (did not finish)

• 6 eggs

• 2 bars of dark chocolate (72% and 85%)

• 2 protein-style double-doubles at In-n-out (the sauce in these might have seed oils)

• about a pound of sliced roast beef

• a blue cheese

• a brie goat cheese

• 4 keto “protein coffees” (no seed oils, I checked)

• maybe more that I forgot.

Yes, I was more than a little sick. But I do it for the science. I couldn’t actually finish the steaks and threw the rest away.

Result: gainz

According to the two DEXA scans, in these 24h, I gained:

Body fat: 0.9lb
Lean mass: 4.4lbs
Muscle mass: 1.4lbs (this is part of lean mass)

Of course it’s unlikely that I gained muscle in any appreciable sense in 24h without ever working out. It’s likely just muscle glycogen and maybe some intra-muscular water retention.

Did I gain 0.9lb of body fat, or was there just some water gain in there as well? Not sure. It might’ve even have been that my stomach had 0.9lb of beef/dairy fat in it, not sure if the machine can tell.

Conclusion

Pretty much what I expected. The DEXA scan is just as noisy as other methods. It’s good to set a baseline, e.g. your rough body fat percentage. But in this example, my body fat actually went down because I “gained 4.4lbs” of lean mass.

Ok, maybe my pre/post protocol is a bit extreme. But so are my usual weight swings when I’m not on ex150, and when I go off. People change up the foods they eat all the time. You’d be highly likely to have different amounts of hydration/water retention/muscle glycogen/intra-muscular water storage/food in your stomach on a day-to-day basis, even if you’re not me. This is more relevant the more dysregulated/hypo/hyperphagic your eating patterns are. Which they likely are if you’re reading a blog by a guy who’s main claim to fame is eating bowls of whipped cream.

So we shouldn’t presume that the DEXA is 100% accurate or “true” from day to day any more than the scale. Sure, you can probably see a trend over months of weight loss. But if you went into one every day, you’d see there’s just as much daily fluctuation and noise as in the scale or the tape measure.