Among middle-aged men who lift weights and eat fewer calories, levels of testosterone rise and insulin levels fall, whether they follow a ketogenic diet or a different type of low-calorie diet.
Mechanism
Synthesis from 1 study
When middle-aged men who lift weights eat fewer calories, their bodies make less insulin, which tells their brain to signal the testes to produce more testosterone — this happens whether they eat low-carb fat-heavy food or just eat less overall, as shown in the study with DOI...
Most probable mechanism
When middle-aged men who lift weights eat fewer calories, their bodies make less insulin because they're not eating as much food, especially carbs. Lower insulin tells the brain to increase signals that tell the testes to make more testosterone, and this happens whether they eat low-carb fat-heavy food or just eat less overall. This is shown in the study with DOI 10.1016/j.clnu.2021.02.028.
Calorie restriction reduces circulating insulin levels due to decreased glucose availability and reduced demand for insulin secretion — supported by 10.1016/j.clnu.2021.02.028
Lower insulin levels reduce inhibition of the hypothalamic-pituitary-gonadal (HPG) axis, increasing gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion — supported by 10.1016/j.clnu.2021.02.028
Increased LH stimulates Leydig cells in the testes to produce more testosterone, elevating basal and free testosterone levels — supported by 10.1016/j.clnu.2021.02.028
Evidence from Studies
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