Here’s how your body makes testosterone: cholesterol→ pregnenolone→ androstenedione→ testosterone.

Testosterone begins with cholesterol. In fact, you synthesize every single sex hormone from cholesterol. This is one reason that a “heart healthy” low-fat, low-cholesterol diet is horribly aging. Research confirms that men who eat saturated fat, monounsaturated fat, and cholesterol have higher testosterone levels than those who follow a low-fat diet.

• Jeff S. Volek et al., “Testosterone and Cortisol in Relationship to Dietary Nutrients and Resistance Exercise,” Journal of Applied Physiology 82, no. 1 (1997): 49–54, https://doi.org/10.1152/jappl.1997.82.1.49.