Do Ultra Processed Foods Lower Testosterone?

Eating a diet high in ultra-processed foods (UPFs) is linked to lower testosterone levels and poorer sperm quality in adult men, according to recent controlled trials. However, the effect isn’t universal, studies in adolescents show a different hormonal picture, and the amount of calories you eat alongside UPFs changes the severity of the impact.

The link is strongest in studies of reproductive-age men. In one trial, men eating an ultra-processed diet had reduced circulating testosterone levels, raising the question: do ultra processed foods lower testosterone? More consistently, that same diet significantly reduced sperm motility. The evidence points to a real effect, but it’s tangled up with other factors like overall diet quality and whether you’re in a calorie surplus.

What follows is a breakdown of the specific numbers from those studies, a look at where the research disagrees (especially for women and younger people), and a practical method for identifying and swapping out UPFs in your own diet without turning meals into a chore.

Key Takeaways

• In a controlled trial, an ultra-processed diet providing 77% of calories from UPFs was studied; research indicates that UPF consumption adversely affects sperm quality and reduces circulating testosterone levels.
• Replacing just 10% of energy from UPFs with unprocessed foods is associated with better sperm count, concentration, and motility.
• The testosterone-lowering effect is most clear in adult men; however, research disagrees on the effect in adolescents, with one study finding UPF intake was linked to higher bioavailable testosterone in girls.
• All macronutrients, protein, carbs, and fat, cause a short-term drop in testosterone after eating, with protein causing the most prolonged suppression.
• Research suggests the negative hormonal and sperm effects may be more pronounced when UPFs are consumed with excess calories.

What the Controlled Trial Data Shows

The most direct evidence comes from a 2025 randomized controlled trial highlighted in Nature Reviews Urology. Researchers put 43 men on two different diets for three weeks each. One diet was ultra-processed: 77% of calories came from UPFs and only 5.5% from unprocessed foods. The other was an unprocessed diet, with just 1% of energy from UPFs and 66% from whole foods.

To isolate the effect of the food itself from just eating more, the men followed each diet at two calorie levels: adequate for their needs and in excess. The results were telling. On the UPF diet, circulating testosterone levels were reduced. The more striking finding was on sperm: the ultra-processed diet adversely affected sperm quality.

This trial design is key. By controlling calories, it shows the UPF effect isn’t just about weight gain. The food processing itself, or what’s lost or added in that process, seems to drive the hormonal and reproductive change.

This aligns with a large observational study, the Led-Fertyl study, which looked at diet and semen quality. It found that in the Led-Fertyl study, sperm concentration and motility were lower in participants in the highest tertile of UPF consumption compared to the lowest. More importantly, it modeled a change: theoretically replacing 10% of energy from UPFs with 10% from unprocessed foods was associated with higher total sperm count, concentration, and motility. That’s a relatively small swap with a measurable potential benefit.

The Biological Mechanisms: More Than Just Fat

If UPFs lower testosterone, how does it work? The classic explanation points to obesity and inflammation. Excess body fat increases the conversion of testosterone to estrogen. Chronic inflammation from poor diet can disrupt the hormonal signaling between the brain and the testes. This is a valid pathway, supported by the well-documented link between obesity and lower T.

But newer research suggests a more immediate, meal-by-meal mechanism. A 2022 study in the Journal of the Endocrine Society gave 11 healthy men 400-calorie drinks of pure dextrose (sugar), protein, or lipid (fat) after a fast. All three lowered serum testosterone compared to water. Protein caused the biggest and longest drop, a decrease of 80 ng/dL at 200 minutes, with suppression lasting over five hours.

Common mistake: Blaming only dietary fat. While a high-fat “fast food” meal can suppress testosterone, this study found protein caused a deeper, longer drop. The body’s acute hormonal response to eating any concentrated macronutrient load appears to be a brief testosterone dip.

This acute suppression appears independent of LH (the brain’s signal to make testosterone), suggesting a direct testicular or metabolic effect. When you eat a UPF, which is often a concentrated hit of refined carbs, poor-quality fats, and protein isolates, you may be triggering this suppression multiple times a day, which is central to the do ultra processed foods lower testosterone debate. Over time, that could contribute to a lower baseline. This acute effect also helps explain why simply avoiding seed oils or sugar in isolation isn’t a complete fix, the problem is the overall matrix of the food.

Where the Research Disagrees (And Why It Matters)

Not every study finds a straight line from UPFs to lower testosterone. The disagreement highlights that context, age, sex, and overall diet, changes everything.

The biggest conflict is in younger populations. While several adult male studies show a lowering effect, research disagrees on the effect in younger populations; a 2024 cross-sectional study in Frontiers in Nutrition of kids and teens found something different. In female adolescents, higher UPF intake was significantly associated with an increased Free Androgen Index (FAI) (Q4 vs. Q1: β = 9.5, 95%CI: 1.5, 17.6), indicating higher bioavailable testosterone levels. The study found no associations between UPF consumption and total testosterone (TT), estradiol (E2), or the TT/E2 ratio, both in males and females. This is the opposite directional effect seen in men.

Population	Study Type	Observed Effect on Testosterone/Androgens	Key Caveat
Adult Men	Randomized Controlled Trial (Cell Metabolism)	Trend toward lower circulating testosterone	Effect clearer in excess-calorie condition
Adult Men	Observational (Led-Fertyl)	Lower sperm quality linked to high UPF intake	Replacing 10% UPF energy improved parameters
Adolescent Girls	Cross-Sectional (Frontiers in Nutrition)	Higher Free Androgen Index (bioavailable T)	No change in total testosterone observed
Healthy Men (Acute)	Controlled Feeding (Journal of Endocrine Society)	Acute drop after any macronutrient drink	Protein caused longest suppression (320 min)

There’s also debate on the role of fat. One line of research suggests a high-fat ‘fast food’ meal can cause a substantial fall in testosterone, while other studies indicate the effect of lipid ingestion is minimal. But the 2022 Journal of the Endocrine Society study found the lipid drink caused only a minimal 10 ng/dL decrease at 70 minutes. Sources disagree on the mechanism and potency of fat’s effect on testosterone suppression, with one suggesting an indirect intestinal mechanism from mixed meals and another finding oral lipid ingestion causes only a minimal decrease.

These disagreements mean blanket statements are misleading. For an adult man concerned with fertility, the evidence is strong enough to act on. For a teenage girl or someone eating at maintenance calories, the hormonal picture is more complex and less clearly negative, especially when you compare a do ultra processed foods lower testosterone study in men to one in adolescents. This nuance is often missing from scare headlines about foods that lower testosterone.

How to Actually Reduce Your UPF Intake

Knowing UPFs are bad is one thing. Avoiding them in a supermarket aisle is another. The NOVA classification system, used in the research, gives us a practical filter. It splits food into four groups: unprocessed or minimally processed foods (NOVA 1), processed culinary ingredients (NOVA 2), processed foods (NOVA 3), and UPF (NOVA 4).

Start by reading ingredient lists, not just nutrition labels. A long list with unrecognizable ingredients is your first clue. Second, consider the product’s form. Can you make it in a home kitchen with basic ingredients? You can bake bread or fry a potato. You cannot make a Cheeto or a protein bar that tastes like a cookie.

Here is a simple swap strategy that doesn’t require cooking every meal from scratch:

• Breakfast: Swap sugary cereal (UPF) for plain oatmeal (NOVA 1) topped with fruit and nuts. Swap a protein bar (UPF) for Greek yogurt (NOVA 1) or a couple of hard-boiled eggs.
• Lunch: Swap packaged deli meat and white bread (UPF) for canned tuna (NOVA 3) on whole-grain bread (often NOVA 3 or 4, check the label!). A better move is leftovers from last night’s dinner.
• Snacks: Swap chips and crackers (UPF) for whole fruit, nuts, or sliced vegetables with hummus (minimally processed).
• Drinks: Swap soda, energy drinks, and most commercial smoothies (UPF) for water, sparkling water, or coffee/tea.

The goal isn’t perfection. It’s shifting the balance. As the Led-Fertyl study suggested, a 10% shift in energy from UPFs to whole foods can matter. That might mean two fewer UPF-based meals per week. This approach is more sustainable than any rigid testosterone diet plan.

The Calorie Context: When “How Much” Changes Everything

The 2025 Cell Metabolism trial was designed to isolate effects of UPFs from caloric intake, with research suggesting caloric load may interact with UPF consumption to worsen outcomes. This means eating too many calories of UPFs is worse than eating a maintenance amount of them.

It creates a vicious cycle. UPFs are engineered to be hyper-palatable and easy to overeat. That overconsumption leads to weight gain, which independently lowers testosterone. The study suggests the calorie excess and the UPF ingredients then work together to do more damage to reproductive health than either would alone. This is a strong argument for paying attention to portion size if you do include some UPFs. It also means that for men trying to optimize hormones, getting calories under control is step zero, before worrying about specific nutrient deficiencies or superfoods.

Ultra-Processed Foods vs. Other Lifestyle Factors

Where does UPF consumption rank on the list of testosterone killers? It’s significant, but it doesn’t operate in a vacuum. It amplifies and is amplified by other poor lifestyle choices.

Sleep deprivation, for example, reliably lowers testosterone. A review in Reviews in Endocrine and Metabolic Disorders notes that sleep deprivation leads to reduced testosterone levels and that UPF intake has been linked to decreased testosterone concentrations. They both promote inflammation and insulin resistance. If you’re eating poorly and sleeping poorly, you’re hitting the same biological systems from two angles.

Chronic stress is another major player. It raises cortisol, which directly competes with testosterone production. A diet high in UPFs can be a source of physical stress (via inflammation) and often coincides with the rushed, high-stress lifestyle that leads to poor food choices.

So, is it the #1 enemy? Probably not for everyone. For a young, lean, active man who sleeps well, moderate UPF intake might have a muted effect. For a middle-aged man who is overweight, stressed, and sleeps five hours a night, cutting out UPFs could be one of the most impactful single changes he makes, partly because it often improves sleep and body composition. This interplay is a core reason for the broad declining testosterone trends we see, it’s rarely one factor.

Do UPFs contain endocrine disruptors?

However, research has established a link between UPF consumption and lower testosterone levels in adult men. Many plastic packaging materials can leach chemicals that may interfere with hormone function. While the direct evidence from the provided studies focuses on the dietary pattern itself, choosing whole foods over packaged UPFs is a practical step to reduce potential exposure to these industrial chemicals. Opting for fresh produce and ingredients you prepare yourself minimizes contact with materials that could contain hormone-disrupting compounds.

Frequently Asked Questions

What is the #1 testosterone killer?

There isn’t a single universal “killer,” but the most reliable, evidence-backed factor for chronically low testosterone is excess body fat. Obesity drives estrogen up and testosterone down through multiple pathways. For acute, meal-by-meal suppression, concentrated protein intake causes the most prolonged suppression, based on controlled feeding studies. Chronic sleep deprivation is also a top-tier factor.

Do all processed foods lower testosterone?

No. The NOVA classification helps here. “Processed foods” (NOVA 3) like canned beans, cheese, and whole-grain bread are not linked to the same negative effects as “ultra-processed foods” (NOVA 4). The problem is the industrial formulations with additives and ingredients designed to mimic real food. Don’t waste energy worrying about a can of tomatoes.

How much ultra-processed food is too much?

The research hasn’t defined a safe threshold. However, the Led-Fertyl study found benefits from theoretically replacing just 10% of energy intake from UPFs with whole foods. In the controlled trial, the ultra-processed diet provided an average of 77% of calories from UPFs. Research shows the mean percent of total energy intake from UPFs among U.S. Youths is high, at 66.1% in one study. Aiming for below 50% of total energy intake from UPFs is an initial target.

Does this apply to women?

The data is mixed and age-dependent. For adult women, research often focuses on fertility and metabolic health, not testosterone specifically. The surprising finding from the adolescent study was that higher UPF intake was linked to a higher Free Androgen Index in girls. This doesn’t mean it’s “good”, it indicates UPFs may disrupt delicate hormonal balance differently depending on life stage. The general health advice to limit UPFs still stands.

What should I eat instead?

Focus on the first NOVA group: unprocessed or minimally processed foods. Build meals around vegetables, fruits, eggs, meat, fish, whole grains like oats and rice, legumes, nuts, seeds, and plain dairy. Use healthy fats like olive oil and butter. For a list of what to add, not just avoid, see our guide on foods that increase testosterone. The best next step is to audit one typical day of eating, identify the top two UPF sources, and find a simple whole-food swap for each.

The Bottom Line

The evidence that ultra-processed foods can lower testosterone and harm sperm quality in men is solid, particularly when those foods are eaten in excess. The mechanism isn’t just about getting fat, it involves acute hormonal suppression after eating and chronic inflammation.

But the story isn’t simple. If you’re a teenage girl, the same dietary pattern might push androgens in the other direction. If you’re eating at maintenance calories, the effect may be weaker. This complexity is why the answer isn’t a list of “bad” foods, but a framework for making better choices most of the time.

Start with the ingredient list. If it looks like a chemistry experiment, put it back. Swap one UPF-heavy meal this week for something made from recognizable ingredients. That single change mirrors the 10% shift the research links to better outcomes. Chasing perfect hormone optimization while ignoring the foundational impact of diet quality is like tuning a car’s engine but forgetting to put oil in it. Fix the basics first.