2025/09/23 Ultra-Processed Foods Shown to Harm Male Metabolic and Reproductive Health

Ultra-Processed Foods Shown to Harm Male Metabolic and Reproductive Health, Independent of Caloric Intake

A new clinical trial has found that consuming ultra-processed foods (UPFs) negatively affects men’s cardiometabolic and reproductive health—even when calorie intake is carefully controlled. Conducted with a randomized 2 × 2 crossover design, the study assigned 43 healthy men to alternate between three-week diets composed mainly of ultra-processed or unprocessed foods, under both normal and excessive caloric conditions. By keeping total calories and nutrient profiles consistent across diets, the trial isolated the role of food processing itself from that of energy intake.
 
The findings were striking. Participants on the UPF diet gained weight and fat mass, while also showing an unfavorable shift in cholesterol ratios. These effects appeared regardless of whether their caloric load was adequate or excessive, suggesting that the processed nature of the foods themselves drives metabolic disruption. In addition to weight and cholesterol changes, levels of key reproductive hormones declined: follicle-stimulating hormone dropped in the excess-calorie arm, while testosterone levels trended downward in the adequate-calorie arm. Sperm motility also showed a decrease, raising concern that UPFs may contribute to the long-documented global decline in semen quality.
 
The study went beyond metabolic and reproductive outcomes to examine pollutants and mood. Men consuming UPFs showed higher serum concentrations of a phthalate metabolite (cxMINP), a chemical linked to endocrine disruption, and lower levels of lithium, a trace element involved in mood regulation. Some participants also reported higher depression scores. These changes point to a complex set of biological effects, suggesting that UPFs may impair health through multiple pathways, including hormonal imbalance and increased exposure to food-borne contaminants.
 
Although the intervention lasted only three weeks, the consistency of these changes across different health domains raises concern about potential long-term risks if UPFs remain a major part of the diet. Given that such foods already account for over half of daily caloric intake in many high-income countries, the implications are significant for public health. The results also build on population studies linking UPF consumption to obesity, cardiovascular disease, cancer, and mental health disorders, providing stronger causal evidence from a controlled trial.
 
“By showing that the harmful effects of UPFs occur independently of calorie intake, our study highlights the unique dangers of industrially processed foods,” the authors concluded. “Shifting dietary habits toward less-processed alternatives may not only support cardiometabolic health but also help safeguard mental well-being and male reproductive fitness.”
 
https://www.sciencedirect.com/science/article/pii/S1550413125003602?via%3Dihub