Low Protein in Puberty Lowers Testosterone Levels in Adults

[Jinzang]

The study was conducted on lab rats, not men, but still is interesting. Lab rats were either fed a low protein diet (4% of calories) during puberty only or a normal protein diet (20% of calories) throughout life. The lower protein group had lower testosterone levels and suffered from metabolic disorders though life. The abstract says:

We examined the long-term effects of protein restriction during puberty on the function of hypothalamic–pituitary–adrenal (HPA) and hypothalamic–pituitary–gonadal (HPG) axes in male rats. Male Wistar rats from the age of 30 to 60 days were fed a low-protein diet (4%, LP). A normal-protein diet (20.5%) was reintroduced to rats from the age of 60 to 120 days. These rats exhibited hyperactivity of the HPA axis, hypoactivity of the HPG axis and a weak insulinotropic response (P < 0.01). LP rats at the age of 120 days were hyperphagic and exhibited higher visceral fat accumulation, hyperleptinemia and dyslipidemia; lower blood ACTH, testosterone and testosterone release; and reduced hypothalamic expression of AR, GR and SOCS3, with a higher pSTAT3/STAT3 ratio (P < 0.05). The hyperactivity of the HPA axis and the suppression of the HPG axis caused by protein restriction at puberty contributed to energy and metabolic disorders as long-term consequences.