Daijiworld Media Network - Copenhagen

Copenhagen, Aug 31: A new study warns that even small amounts of ultra-processed foods can lead to weight gain, hormonal disruption, and poor sperm quality in men, regardless of calorie intake.

The international study, published in Cell Metabolism, found that people consuming ultra-processed diets gained more weight than those on minimally processed diets, even when eating the same number of calories. The research also revealed that such diets introduce higher levels of pollutants, known to negatively affect sperm quality.

Lead author Jessica Preston of the University of Copenhagen’s NNF Center for Basic Metabolic Research (CBMR) said, “Our results prove that ultra-processed foods harm our reproductive and metabolic health, even if they’re not eaten in excess. It is the processed nature of these foods that makes them harmful.”

The study involved 43 men aged 20–35, who spent three weeks on ultra-processed and unprocessed diets each, with a three-month washout period in between. Some participants were given a high-calorie diet, while others received standard calories for their size and activity level. Both diets contained identical calories, protein, carbs, and fats.

Men on the ultra-processed diet gained roughly 1 kg more fat compared to the unprocessed diet group, regardless of calorie intake. Cardiovascular health markers were also negatively affected. Researchers observed increased levels of the hormone-disrupting chemical phthalate cxMINP and decreases in testosterone and follicle-stimulating hormone, both critical for sperm production.

Professor Romain Barrès of the University of Copenhagen expressed concern, saying, “We were shocked by how many body functions were disrupted by ultra-processed foods, even in healthy young men. The long-term implications are alarming and highlight the need to revise nutritional guidelines to better protect against chronic disease.”