When It Comes To Body Fat, Less Is Not Always More

When it comes to body fat and metabolic health, this is not an entirely new revelation, for example we have previously discussed: How To Make Your Body Fat Heart-Healthier

So what’s the new news?

Lean mass isn’t always better for metabolic health

Regular 10almonds readers will know already that lean muscle mass is generally good for metabolic health, for the reason that muscle “costs” energy to maintain, so having more lean muscle mass means (all else being equal), that your metabolic base rate is higher, which is generally healthier.

However, all else is not always equal!

Researchers (Dr. Sri Lakshmi S Devarakonda et al.) did a cross-sectional analysis of 59,269 UK Biobank participants, using DXA and MRI measurements to examine the relationships between fat-free* mass, fat distribution, and metabolic health.

^{*Fat-free mass (FFM): includes all nonfat components of the body, including muscle, bones, and organs, and is often used as an indirect measure of muscle mass because muscle makes up the largest proportion of FFM in most adults.}

However, there were some unexpected findings: higher total FFM and FFM adjusted for height were associated with a greater prevalence of metabolic syndrome and elevated HbA1c. On the flipside, a higher proportion of body weight consisting of FFM was associated with a lower prevalence of both conditions.

Some of this seems to have to do with different kinds of fat and the locations thereof, per:

• Visceral adipose tissue (VAT): fat stored deep within the abdomen around internal organs had the strongest influence on the relationship between FFM and metabolic health.
• Muscle fat infiltration (MFI): fat accumulating within muscle tissue also modified the associations between FFM and adverse metabolic outcomes, although some effects became weaker after accounting for visceral fat.

As the study authors put it:

❝Our findings show that the adverse metabolic outcomes associated with FFM are not inherent to FFM itself but are heavily shaped by visceral adiposity, muscle composition, and the specific FFM metric.❞

Sex hormones also played a role: testosterone, sex hormone–binding globulin, and estradiol had modest, measurement-specific modifying effects on the relationships between FFM and metabolic outcomes. This is also consistent with some of the things we’ll link below in just a moment.

First though, if you’d like to read this paper in full, here it is: Relationship between fat-free mass and metabolic syndrome is shaped by ectopic fat in a UK Biobank cohort

What to do about it

Firstly, see our previous article: Visceral Belly Fat & How To Lose It for the dos and don’ts of getting healthier (which for most people means: lower) visceral fat levels.

Next up, see also: Body Fat & Pelvic Floor Problems: What Matters Most Is Where The Fat Is for more about those “apple or pear” distributions, and how to switch it up.

You may also be wondering: Can We Do Fat Redistribution? And the answer is yes, and we are doing it all the time whether we want to or not, so we might as well know what things affect our fat distribution in various body parts. The article we just linked there shows how.

While we’re at it, one other place you really don’t want excess fat, for metabolic reasons, is your liver. So: How To Unfatty A Fatty Liver

Take care!