They also saw declines in hormones linked to sperm production and testicular function<\/p>\n
Together, these decreases could lead to diminished sex drive and muscle mass, as well as impaired fertility<\/a> and cognitive function.\u00a0\u00a0<\/p>\n The team also found that those eating a highly-processed diet had more phthalates in their blood, which can disrupt hormones and affect fertility.\u00a0<\/p>\n These effects were not seen in the same group eating a largely unprocessed diet, even though the diets were matched for calories and nutrients.<\/p>\n Dr Jessica Preston, a metabolism researcher and lead author of the study, said: ‘Our results prove that ultra-processed foods harm our reproductive and metabolic health, even if they’re not eaten in excess.<\/p>\n ‘This indicates that it is the processed nature of these foods that makes them harmful.’<\/p>\n Researchers said that ultra-processed foods tend to contain very little fiber, unlike whole foods, which helps to make them highly palatable, but can also mean someone absorbs more calories from a meal, causing weight gain.<\/p>\n Scientists said that eating an ultra-processed diet raised the risk of weight gain and fertility problems in males (stock image)<\/p>\n Your browser does not support iframes.<\/p>\n Ultra-processed foods today make up a major part of the American diet, with the CDC saying they account for 55 percent of daily calories.<\/p>\n In the study, published in the journal Cell Metabolism<\/a>, participants were asked to eat a majority ultra-processed diet for three weeks and then a majority unprocessed diet for the same period, with a three-month gap between the two.<\/p>\n The unprocessed and ultra-processed diets were matched to contain exactly the same number of calories, proteins, carbohydrates and fats.<\/p>\n But the men were split into two groups, with one group only consuming the amount their bodies needed while the second consumed 500 extra calories while on both diets.<\/p>\n The largely unprocessed diet included scrambled eggs, bananas, salads with chickpeas and chopped mango or pineapple.<\/p>\n While the largely ultra-processed diet was made up of foods including protein bars, pulled pork, bread, barbecue sauce, candies and coleslaw.<\/p>\n Additionally, compared to the unprocessed diet, the ultra-processed diet contained more saturated fat, cholesterol, added sugars, and dairy, and lower amounts of fiber.\u00a0<\/p>\n The researchers said their aim was for at least 75 percent of calories to be derived from processed foods or unprocessed foods in either diet plan.\u00a0<\/p>\n The above graphic is a sketch of what a standard meal looked like on the largely unprocessed and largely ultra-processed diets<\/p>\n Overall, compared to when they ate unprocessed diets, the men gained an average of 3lbs and 2.2lbs of fat when they followed the processed diet.\u00a0\u00a0<\/p>\n They also had drops in the follicle-stimulating hormone, FSH, and in testosterone compared to the largely unprocessed diet group.<\/p>\n These hormones regulate sexual function and the production of sperm, with researchers warning that this decline could affect a man’s libido and fertility.<\/p>\n Researchers also found those on the largely ultra-processed diet had higher blood levels of cxMINP, a type of phthalate added to food packaging to make them more flexible that can disrupt hormones in humans.<\/p>\n Those on the high-calorie ultra-processed diet also had reduced sperm motility, or a reduction in sperm’s ability to transport.<\/p>\n Those who ate a largely unprocessed diet had higher levels of mercury in their blood, which has been linked to neurological problems at higher concentrations, although these didn’t reach levels to concern the scientists.<\/p>\n This is likely because this diet contained more fish, which contains higher levels of the substance.\u00a0<\/p>\n The decreases in hormones observed in men eating an ultra-processed diet could lead to diminished sex drive and muscle mass, as well as impaired fertility and cognitive function<\/p>\n![\"Scientists](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/08\/101667511-15047185-image-a-4_1756479132044.jpg\")
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