Disappointment, or error?

Dear Doctor Ninja,

I am a reasonably fit 57 year old male. Nearly three years ago, I had a DEXA scan that revealed I had about 500g of visceral fat. It didn't seem critical that I lose it, but I thought it would definitely be good if I reduced it. Between the scan and November last year, I hiked 1000km over four separate hikes, rode my bicycle a lot, became a vegetarian and generally reduced drinking alcohol. In November last year, I started an intensive 12-week workout program, which included five weight-training workouts and one aerobic workout every week. I also didn't have an alcoholic drink for 100 days. Then I had another DEXA scan. I felt sure that my visceral fat level would have dropped. Instead, it was 160g more, causing me to exclaim mutha-ninja! Would you have any advice on the best ways to reduce visceral fat?


Fujibayashi Nagato

First off, congratulations on making some great lifestyle changes that seem to be working for you!

Before I get into your question, I think it’s important to note a number of reasons why you might have been disappointed in your perceived lack of progress.

In an ideal situation, if you wanted to know how effective your 12-week program was going to be, you would have done a DEXA scan before you started. Since it’s been 3 years and a bit since your DEXA, we really don’t have a good idea of what your visceral fat has been doing. Were you possibly even higher than 660 grams 12 weeks ago?

The other consideration is the nature of the DEXA scan itself. Again, in an ideal situation, you would have a DEXA scan with the same scanner, as different scanners use different algorithms to calculate the various tissue masses. You didn’t mention if this was a whole-body DEXA scan or a single-level one, which can also affect things, particularly if your previous scan was one and your latest scan was the other.

Even measurements with the same machine carry measurement error though. Fat mass variation between scans of the same person (with no change in body composition) can be in the 150g range, which means that an increase of 160g of visceral fat from your previous scan 3 years ago could be due to just the variation in the machine, as opposed to an actual meaningful increase in visceral fat.

You can’t reduce your visceral fat to 0. The average amount of visceral fat in healthy 20-30 year old males likes somewhere in the 400g range. You’re not 20-30 years old anymore, so the average amount of visceral fat in a healthy 50-60 year old male is expected to be higher as visceral fat tends to increase as we age, even if our waistlines don’t.

Visceral fat is contrasted from the fat that sits under the skin (the fat you can pinch, also called subcutaneous fat). It’s the fat around your organs. Visceral fat plays an essential role in organ health as both a source of energy as well as padding; it’s only when visceral fat is in _excess_ that it becomes a problem. Its accumulation is directly related to fat accumulation in general. There’s no known effective way to directly target visceral fat without making changes in other fat stores.

Fat, in general, does not accumulate when there’s no difference between the energy you’re spending vs the energy you’re eating. So the best ways to prevent visceral fat accumulation, or to reduce it, are the same ways to lose fat in general, which come down to controlling the “energy in vs energy out” equation. While there are still many small controversies about which diet is best and whether there can be ways of trying to get around this energy balance requirement, it still seems to bear out that it’s the main linchpin of the matter. How you choose to manipulate energy balance (whether through vegetarianism, or carnivorism) depends mostly on the priorities you have on what, of many factors, play into whether you can stick to an eating style or not. “Diets” are mostly mind-tricks that we use to allow us to execute a habit of eating within energy balance—some people need different or stricter rules than others.