Research Links Ultra-Processed Foods to Male Weight Gain

New research indicates that diets high in ultra-processed foods contribute significantly to fat gain in men, disrupt hormonal balance, and may introduce harmful substances linked to declining sperm quality. This study underscores the notion that not all calories are equal, revealing that ultra-processed foods can have detrimental effects on men’s health.

The findings, published in the journal Cell Metabolism, demonstrate that men consuming large quantities of ultra-processed foods gain more fat compared to those who eat unprocessed meals, even when calorie intake is identical. The research indicates a shift in male hormone levels, with testosterone levels declining and pollutants increasing in those on an ultra-processed diet.

Study Details and Methodology

In an effort to understand the effects of diet more comprehensively, researchers at the University of Copenhagen conducted a study involving 43 men aged between 20 and 35. Each participant followed both ultra-processed and unprocessed diets for three weeks, separated by a three-month washout period. Participants were divided so that half started with the ultra-processed diet while the other half began with the unprocessed option.

The diets were meticulously controlled, with both types containing equal amounts of calories, protein, carbohydrates, and fats. Interestingly, half of the men were given a high-calorie diet with an additional 500 calories per day, while the other half maintained their normal caloric intake based on size, age, and activity levels. The results were clear: men on the ultra-processed diet gained approximately 1 kg more fat mass compared to those on the unprocessed diet, regardless of caloric consumption.

Health Implications and Concerns

The implications of this research extend beyond weight gain. A larger analysis published in the British Medical Journal in 2024, which surveyed 9.9 million individuals globally, found that ultra-processed foods are associated with a higher risk of mortality from cardiovascular diseases, obesity, type 2 diabetes, sleep disturbances, anxiety, and depression.

Lead researcher Jessica Preston emphasized the significance of their findings: “Our results prove that ultra-processed foods harm our reproductive and metabolic health, even if they’re not eaten in excess. This indicates that it is the processed nature of these foods that makes them harmful.”

Moreover, the study uncovered concerning increases in the hormone-disrupting substance cxMINP, commonly found in plastics, among men consuming ultra-processed diets. This group also showed declines in both testosterone and follicle-stimulating hormone levels, critical for sperm production.

As these findings shed light on the adverse effects of ultra-processed foods, they raise critical questions about current nutritional guidelines. The long-term health implications suggest a pressing need for revisions to better protect against chronic diseases linked to dietary choices.

The comprehensive nature of this research highlights the importance of understanding the differences between processed and unprocessed foods. As more evidence accumulates, it becomes increasingly clear that the processing itself—not merely overeating—is a significant factor in the observed health outcomes.