Effects of Lifestyle, Diet, and Body Composition on Free Testosterone and Cortisol Levels in Young Men.

Free testosterone concentration was negatively correlated with body fat content in young men.

• Study included 40 healthy male volunteers aged 18-35 years.
• Body composition analysis was performed alongside biochemical determination of serum free testosterone concentrations.
• The negative correlation between free testosterone and body fat content was statistically significant.
• Anthropometric measurements were used to assess body composition parameters.

Free testosterone concentration was positively correlated with the percentage of energy, protein, fat, sodium, and folic acid requirements met.

• Dietary data were collected using a 3-day food diary and a food frequency questionnaire.
• The correlation was observed for multiple macronutrient and micronutrient intake variables.
• Folic acid intake was among the specific micronutrients positively associated with free testosterone.
• Sodium intake was also positively correlated with free testosterone levels.

Morning blood cortisol levels were negatively correlated with body weight and height.

• Serum cortisol concentrations were measured in morning blood samples.
• Both body weight and height showed negative correlations with morning cortisol levels.
• Greater muscle mass was also correlated with lower cortisol levels.
• Higher body weight was associated with lower cortisol levels.

Higher intakes of cholesterol, folic acid, and vitamin A resulted in statistically significant reductions in cortisol levels.

• Dietary intake was assessed via a 3-day food diary.
• Three specific dietary components—cholesterol, folic acid, and vitamin A—were each associated with lower cortisol.
• The reductions in cortisol associated with these nutrients were described as statistically significant.
• Folic acid was notably associated with both free testosterone (positive) and cortisol (negative) levels.

Poor sleep quality was significantly correlated with low cortisol levels, particularly among men aged less than 26 years.

• Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI).
• The association between poor sleep quality and low cortisol was age-dependent, being more pronounced in the younger subgroup (age < 26 years).
• This finding suggests an age-modifying effect on the sleep-cortisol relationship.
• The PSQI is a validated questionnaire instrument used in the study.

A positive correlation was found between leisure-time physical activity and testosterone levels, particularly in the older age group.

• Physical activity was assessed using the Baecke Physical Activity Questionnaire.
• The positive association between leisure-time physical activity and testosterone was stronger in older participants within the 18-35 year age range.
• The age-dependent effect suggests differential hormonal responses to leisure activity across the young adult age spectrum.
• Stress levels were assessed using the PSS-10 and the Holmes and Rahe Scale alongside physical activity measures.

The study population consisted of 40 healthy young male volunteers aged 18-35 years who underwent a comprehensive multi-method assessment.

• Participants underwent anthropometric measurements and body composition analysis.
• Biochemical determination of serum free testosterone and cortisol concentrations was performed.
• Validated questionnaires included the PSS-10, Holmes and Rahe Scale, PSQI, Baecke Physical Activity Questionnaire, and a food frequency and stimulant consumption questionnaire.
• A 3-day food diary was used to capture dietary intake data.