Ultra-processed Foods Can Lead to Weight Gain, Disrupt Hormone Balance, and Reduce Sperm Quality

Over the past 50 years, obesity and type 2 diabetes rates have risen sharply, while sperm quality has declined significantly. These changes may have been caused by the increasing popularity of highly processed foods, which are associated with a range of negative health effects. However, scientists are still unsure whether this is due to the industrial nature of the ingredients themselves, the processing of the foods, or the fact that they cause people to eat more than they should.

Ultra-Processed Foods Have a Negative Impact on Our Reproductive and Metabolic Health

An international team of scientists has now found that people who eat a highly processed diet gain more weight than those who eat a minimally processed diet, even when they consume the same number of calories. The human study also found that a diet high in highly processed foods leads to higher exposure to pollutants known to impair sperm quality. The results were published in the journal Cell Metabolism.

Our findings demonstrate that ultra-processed foods impair our reproductive and metabolic health, even when consumed in moderation. This suggests that it is the way these foods are processed that makes them harmful,” says Jessica Preston, lead author of the study, who conducted the research during her PhD at the NNF Center for Basic Metabolic Research (CBMR) at the University of Copenhagen.

Contaminated With Endocrine Disruptors

To obtain the best possible data, the scientists compared the health effects of unprocessed and ultra-processed diets in the same person. They recruited 43 men aged 20 to 35, each of whom followed one of the two diets for three weeks, with a three-month “washout period” in between. Half started with the ultra-processed diet, the other half with the unprocessed diet. Half of the men also received a high-calorie diet with 500 extra calories per day, while the other half ate the normal amount of calories for their height, age, and physical activity level. The men were not told which diet they were receiving. Both the unprocessed and ultra-processed diets had the same amount of calories, protein, carbohydrates, and fat. The men gained about 1 kg more fat mass during the ultra-processed diet than during the unprocessed diet, regardless of whether they followed a normal or high-calorie diet. Several other markers of cardiovascular health were also affected.

The scientists also found a worrying increase in levels of the hormonally active phthalate cxMINP, a substance used in plastics, in men who ate ultra-processed foods. Men who ate this diet also had lower levels of testosterone and follicle-stimulating hormone, which are crucial for sperm production. The researchers were shocked by how many bodily functions were disrupted by ultra-processed foods, even in healthy young men. The long-term effects are alarming and underscore the need to revise dietary guidelines to ensure better protection against chronic diseases.