Healthy fats are crucial for testosterone production. Quality sleep is essential for overall hormone balance, including this key androgen. These severe energy restrictions, similar to those experienced during U.S. A deficiency in these nutrients can contribute significantly to lower testosterone levels. Men who undereat often miss out on vital nutrients critical for maintaining optimal hormone levels, such as zinc, magnesium, and vitamin D. These interacting mechanisms illustrate why the hormonal response to dieting is rarely straightforward and is influenced by the individual's starting metabolic health, training load, and dietary composition. The concept of low energy availability (LEA) — defined as insufficient dietary energy relative to exercise energy expenditure, typically below 30 kcal per kg of fat-free mass per day — is recognised as a primary driver of hormonal disruption in both male and female athletes. When caloric intake drops significantly, the hypothalamus may reduce the pulsatile release of gonadotrophin-releasing hormone (GnRH), leading to downstream reductions in luteinising hormone (LH) and, consequently, testosterone synthesis. Several physiological changes converge in your 40s that collectively make fat loss harder. Periodically reassessing your calorie goals and activity levels is best for continued progress. Your first meal post-training should be protein-rich to capitalize on both the fasted training stimulus and the anabolic rebound of refeeding. Undereating is one of the most potent testosterone suppressors, and a compressed eating window makes adequate caloric intake more challenging. A calorie deficit occurs when you burn more calories than you consume, and it's long been considered a cornerstone of weight loss. The purpose of the present study was to compare the effects of long-term CR and endurance exercise training on sex hormone levels in equally lean healthy individuals to differentiate the effects due to leanness from those due to decreased calorie intake. A calorie deficit can lower testosterone levels, especially when severe or prolonged, due to the body prioritizing essential functions over hormone production. These kinds of studies are notoriously inaccurate and shouldn’t even be published since the human species is extremely inaccurate at estimating its own calorie intake. If you’re experiencing challenges with your nutrition or hormonal health, consider scheduling a complementary discovery call with one of our men’s health nutritionists. Dehydration can negatively impact hormone levels, so aim to drink plenty of water throughout the day. Does the type of exercise matter when trying to maintain testosterone during weight loss? In general, it can take several weeks to months for testosterone levels to return to baseline after a prolonged period of calorie restriction. What is the ideal calorie deficit to avoid lowering testosterone? Cardio burns calories, which increases the overall energy deficit. Excessive cardio, especially when combined with a significant calorie deficit, can contribute to a further decrease in testosterone. Higher protein intake also supports satiety and recovery, making your deficit easier to maintain over time. Protein is acritical component to consider during a weight loss journey. Resistance-type exercise is an effective strategy to prevent weight-loss-induced muscle mass loss. If your training demands 3500 or more calories daily, compressing those calories into an 8-hour window can be physically uncomfortable and lead to undereating by default. Men with high training volumes who struggle to eat enough calories should also approach fasting cautiously. Men who are already lean below 12 percent body fat and eating in a caloric deficit should not add intermittent fasting. The delicate balance between shedding fat and maintaining hard-earned muscle can often feel like walking a tightrope. In all of its simplicity, just get to 8-12% body fat, then eat enough to cover your daily needs so that you don’t get fat, but you’re also not eating too little so that your endocrine system functions as it should. However, what is often left unmentioned, is that the study had only women as subjects (gender differences are hugely important when it comes to hormones). This is because any extra fat mass that you have increases aromatase enzyme activity, which converts testosterone to estrogen. It has been reported that CR protects against the decrease in serum DHEA-s concentration with advancing age in rhesus monkeys. Data from epidemiological studies have shown that serum concentration of DHEA-S rapidly declines with age so that by age 75 yr serum DHEA-S concentration is ~80% lower than at 20 yr (Orentreich et al., 1992). Several nutritional and hormonal factors regulate the hepatic production of SHBG, including monosaccharides, insulin, and IGF-1(Selva et al., 2007; Plymate et al., 1990). Further studies are warranted to understand the long-term effects of the CR-induced reduction in sex hormones concentrations on skeletal and bone mass and strength.
