There is fat in/under the skin, which may be protective, according to a study at the University of Illinois. Then there is fat in/among organs, which probably kills you: https://today.uic.edu/why-is-visceral-fat-worse-than-subcut…
Skinfold caliper measurements have shown me that some people lose visceral fat long before they touch subcutaneous fat. I’ve performed tens of thousands of assessments. During that time, you see patterns which may not make sense at first, but then they pop up in lots of individuals. A lot of people eat up the unhealthy fat around organs while pinches of skin stay the same or “worsen.”
This can be vexing for the layperson or for the coach with little experience. Someone’s pinches go up while they’re down 15lbs AND stronger. What happened here? They lost visceral fat. Likewise, people will mistake weight gain concurrent with improved caliper measurements as lean tissue increases. Nope. Not always. Sometimes people’s visceral fat expanded and pulled the skin tighter.
For the client who really wants to get to the bottom of things, this is where multiple metrics help. DEXA, bodpod, underwater weigh in, bioelectrical impedance are all nice. But frankly, if your midsection circumference measurement plummets while strength and performance improve, your health prospects are looking great EVEN when weight is flat or up.
This gets complex. People will try to judge progress by scale. That is incredibly deceiving. Even circumference metrics can mislead you on limbs, because full glycogen (this isn’t fat) from getting a little stronger will expand the thigh slightly - and this is HEALTHY.
To be clear, if you at your near-current height once had a 26 inch waist, every millimeter beyond that is likely representing visceral fat, unless you are a hulkish muscle-bound freak. Even some of those freaks can still get the waistline down to their high school measurement.
It’s not to say pinches are irrelevant. They are just incomplete. And given the propensity for visceral fat to end you, THAT is more pertinent to health prospects than subcutaneous fat or body weight. That all said, I’ve found that even the most visceral-fat-loss-resistant people will still eradicate fat around the liver, pancreas and heart once they get the skin thin enough and keep going.
On the flip side, concerning aesthetics, loose skin in individuals who lose piles of visceral fat can also be lost in a state of fasting. That should be less the concern.
Because visceral fat will kill you. And subcutaneous may even be protective (up to a point).