[keenmaster]

Metabolism is remarkably stable (relative to popular belief) after your teenage years and until you approach 60. The myth of fast-slowing metabolism in your 30s can be damaging. It reduces people’s sense that they can reverse their weight gain, because “it’s my metabolism lol.”

That being said, if you were legitimately muscular in your 20s and lost most of your muscle as you got older/married/had kids, that can reduce your caloric needs and make it seem like your baseline metabolism is changing more than it is.