Recent research shows that diets high in ultra-processed foods could negatively affect men’s reproductive health by reducing sperm quality, while also contributing to metabolic problems like weight gain and elevated cholesterol.

A study published on August 28 in Cell Metabolism found that consuming ultra-processed foods led to hormonal changes critical for sperm production, even when calorie intake matched that of diets based on unprocessed whole foods.

It’s About Food Quality, Not Just Calories

Dr. Philip Werthman, a Los Angeles-based urologist specializing in male fertility, told Healthline:

“The type of calories you consume matters more than the total calories.”

How the Study Was Conducted

Researchers enrolled 43 healthy men aged 20 to 35. Each participant spent three weeks on a diet heavy in ultra-processed foods and three weeks on an unprocessed whole-food diet, separated by a three-month break. Some participants also consumed an additional 500 calories daily to observe effects of increased intake.

During the ultra-processed food phase, participants gained over a kilogram, saw increases in body fat, and experienced decreases in testosterone and follicle-stimulating hormone (FSH), both vital for sperm health. The study also detected elevated levels of cxMINP—a chemical linked to plastics and hormone disruption—likely coming from food packaging.

Declining Sperm Counts and Processed Foods

Since the 1970s, global sperm counts have dropped by roughly 60%, coinciding with increased consumption of ultra-processed foods and exposure to endocrine-disrupting chemicals. This study strengthens the evidence connecting processed diets with declining male reproductive health.

Kristin Kirkpatrick, a dietitian at Cleveland Clinic, commented:

“Even men who appear healthy are at risk of hormone imbalances when consuming a lot of processed foods.”

Dr. Werthman added:

“Your reproductive system reflects your overall health—weight gain, diabetes, and cholesterol issues all impact fertility.”

Wider Health Implications

The CDC reports that ultra-processed foods account for about 55% of calories consumed by Americans. These products are typically high in sugar, salt, and unhealthy fats but low in fiber and nutrients. Common ultra-processed foods include fast food sandwiches, sugary drinks, snacks, and baked sweets.

Studies have linked such diets to obesity, heart disease, diabetes, stroke, cognitive decline, and thousands of preventable deaths annually.

Tips to Support Male Fertility

Experts recommend:

• Eating nutrient-dense whole foods like fruits, vegetables, and whole grains

• Staying physically active and maintaining a healthy weight

• Avoiding tobacco and limiting alcohol

• Getting adequate sleep and managing stress

• Reducing exposure to heat sources such as saunas and hot tubs

Dr. Werthman concluded:

“Healthy lifestyle choices are vital for both overall and reproductive health.”