This reduction in life expectancy is strongly correlated with obesity. And obesity is strongly correlated with seed oils.
I mention this, because the week prior, I posted a video on how and why I intentionally gained over 20 lbs of fat.
Not all fat gain is the same.
I gained 20+ lbs of fat on beef, eggs, and milk.
My metabolism was revved. I had high energy. And the subsequent fat loss was easy.
Most people with 20+ lbs of excess fat have depressed metabolisms, low energy, and a hard time losing fat.
Why?
It goes back to seed oils and the kind of fat that caused the fat gain.
Seed oils are
high in polyunsaturated fats (PUFA), whereas my diet of beef, milk, and eggs is very low in PUFA and high in saturated fats (SFA).
A diet high in PUFA or high in SFA can both cause fat gain, but the metabolic impact is completely different.