Dr Paul Saladino explains why so many men in their 30s and 40s are dealing with erectile dysfunction and low libido, pointing to a documented generational decline in testosterone that has seen average levels drop roughly 20 to 30 percent over the last few decades. He argues that men a century ago commonly had total testosterone in the high 600s or more, while many modern men sit near 300 or 400, and that this collapse is tightly linked to poor diet, obesity and chronic metabolic dysfunction.