Nutrition Diet: Do Donuts Lower Test? The Scientific Link Between Sugar and Hormones

November 5, 2025 •

4 min read

Studies have shown a significant, temporary drop in circulating testosterone levels after consuming a high dose of sugar, directly linking the indulgence of items like donuts to hormonal fluctuations. A deeper look into nutrition reveals how regular consumption of processed treats impacts overall hormonal health and why a balanced diet is crucial for men.

Quick Summary

Eating high-sugar, processed foods like donuts can cause significant drops in testosterone levels and contribute to long-term hormonal imbalance. A diet rich in refined carbs and trans fats promotes insulin resistance, inflammation, and weight gain, which negatively affects hormone production. Conversely, a balanced, nutrient-dense diet supports healthy testosterone levels.

Key Points

Acute Drop in Testosterone: A single high dose of sugar, comparable to a donut and a sugary drink, can cause a temporary drop in testosterone levels of up to 25% within hours.
Insulin Spike Mechanism: The rapid sugar intake triggers a significant insulin spike, which is believed to suppress testosterone production.
Long-Term Impact: Regular consumption of processed foods, pastries, and other sugary desserts has been linked to chronically lower testosterone levels over time.
Hidden Dangers of Processed Fats: Donuts often contain unhealthy trans fats and polyunsaturated fats, which are also associated with reduced testosterone production and increased inflammation.
The Role of Obesity: A diet high in sugar contributes to weight gain, particularly abdominal fat, which can further lower testosterone levels and create a cycle of ill health.
Prioritize Nutrient-Dense Foods: To support healthy testosterone, focus on a diet rich in whole foods like fatty fish, leafy greens, eggs, and oysters, which provide essential vitamins and minerals.
Embrace Healthy Fats: Including healthy fats from sources like avocados and olive oil is important for hormone synthesis and overall health.
Holistic Lifestyle Matters: Alongside diet, crucial factors for maintaining optimal testosterone levels include regular exercise (especially strength training), getting sufficient sleep, and managing stress.

The Hormonal Impact of Refined Sugars and Processed Fats

While enjoying a donut occasionally is unlikely to cause lasting harm, frequent consumption is tied to several factors that can negatively impact testosterone levels. This is due to the treat's high content of refined sugars and unhealthy fats, which disrupt the body's delicate hormonal balance.

The Insulin-Testosterone Connection

When you consume a donut, your body is hit with a large dose of sugar, causing your blood glucose levels to spike. In response, your pancreas releases a large amount of insulin to move the glucose into your cells. A 2013 study demonstrated that adult males who ingested oral glucose experienced an abrupt drop in total and free testosterone levels. This mechanism suggests that the high insulin response can directly suppress testosterone production. If you are regularly consuming high-sugar foods, these constant spikes and dips can contribute to chronic issues like insulin resistance, a known factor in low testosterone.

The Role of Trans Fats and Inflammation

Beyond sugar, donuts and other baked goods are often made with trans fats or unhealthy polyunsaturated fats from vegetable oils. Research has linked the consumption of these fats to lower testosterone levels. A 2017 study on healthy young men found that higher intakes of trans fatty acids were associated with lower total testosterone. The chronic inflammation that results from a diet high in processed foods can also disrupt hormonal regulation and contribute to declining testosterone levels over time.

How a Donut Lowers Test Levels: The Immediate Effect

Several studies and experts have highlighted the acute effect of a high-sugar load on testosterone. One widely cited finding indicates that consuming just 75 grams of added sugar—the equivalent of a medium donut and a sugary drink—can cause a temporary 25% drop in circulating testosterone within just two hours. While temporary, consistent exposure to these hormonal dips from daily sugar intake can accumulate and contribute to more serious hormonal imbalances over the long run.

Long-term Dietary Effects on Hormonal Balance

The link between diet and testosterone is not limited to immediate effects. A 2018 study found that men who frequently ate bread, pastries, and desserts had lower total testosterone levels. This "Western-style" diet, high in refined carbs, sugar, and unhealthy fats, is associated with increased visceral fat (belly fat) and high insulin levels, both of which can suppress total testosterone. Conversely, a balanced diet rich in whole foods and healthy fats can have a positive impact on hormonal health.

A Nutrition Diet to Support Healthy Testosterone

Instead of refined, sugary treats, a diet focused on whole foods can provide the essential nutrients needed for optimal testosterone production. Balancing your plate with a variety of healthy options is key.

Key Nutrients and Foods

To support natural testosterone production, focus on a diet rich in these nutrients and food sources:

Fatty Fish: Salmon, tuna, and mackerel are rich in Vitamin D and omega-3 fatty acids, which have been shown to support testosterone levels.
Oysters and Shellfish: Excellent sources of zinc, a mineral crucial for testosterone production and reproductive function.
Eggs: A great source of protein and cholesterol (found in the yolk), which is a building block for testosterone.
Leafy Greens: Foods like spinach and kale are packed with magnesium, a mineral that can increase free and total testosterone levels.
Avocados and Olive Oil: These are rich in healthy monounsaturated fats, which support hormonal health.
Onions and Garlic: These contain compounds that may help increase levels of hormones that trigger testosterone production and can reduce cortisol.

The Importance of a Balanced Lifestyle

In addition to dietary changes, other lifestyle factors are crucial for maintaining healthy testosterone levels:

Prioritize Sleep: Testosterone production peaks during sleep, particularly during REM cycles. Aim for 7-8 hours of quality sleep per night.
Get Regular Exercise: Incorporate strength training and moderate cardio into your routine. Exercise helps build muscle and manage weight, both of which positively influence testosterone.
Manage Stress: High levels of cortisol, the stress hormone, can interfere with testosterone production. Practice stress-reducing techniques like meditation or exercise.
Limit Alcohol: Excessive alcohol consumption can negatively impact your hormone system and testicular function.

Choosing Your Fuel: Donut vs. Nutrient-Dense Foods


Feature	Donuts & Sugary Treats	Nutrient-Dense Whole Foods
Nutritional Profile	High in refined carbs, sugar, unhealthy trans fats. Low in vitamins, minerals, and fiber.	Rich in protein, healthy fats, complex carbs, and essential vitamins and minerals.
Impact on Insulin	Causes rapid, significant insulin spikes leading to temporary testosterone drops.	Provides sustained energy release, preventing blood sugar crashes and supporting stable hormone function.
Long-Term Effects	Associated with weight gain, increased visceral fat, chronic inflammation, and lower long-term testosterone.	Supports a healthy body weight, reduces inflammation, and provides the building blocks for optimal hormone production.
Hormonal Health	Directly disrupts hormonal balance, causing short-term suppression and long-term imbalance.	Supports the body's natural hormone synthesis and regulation.

Conclusion: Moderation is Key

So, do donuts lower test? In a high-sugar dose, yes, research indicates they can cause a temporary dip in testosterone. A chronic diet high in refined sugar and processed foods is linked to lower testosterone and overall hormonal dysfunction. The occasional donut is not the main problem, but a pattern of poor dietary choices can have a significant cumulative effect. For long-term health and hormonal balance, prioritize a nutrient-dense diet rich in whole foods, manage your lifestyle with regular exercise and sufficient sleep, and view sugary treats like donuts as an infrequent indulgence rather than a dietary staple.

Frequently Asked Questions

Yes, consuming a single high-sugar item like a donut can cause a significant, temporary drop in your testosterone levels due to the corresponding insulin spike.

The drop in testosterone levels after consuming sugar is temporary. Studies show that the levels can be suppressed for up to two hours following a significant sugar intake.

When you eat a large amount of sugar, your body releases insulin. High insulin levels are known to suppress the body's natural production of testosterone, causing the observed dip.

Yes, studies have shown a link between a high intake of trans fats, often found in processed foods like donuts, and lower testosterone levels.

Lifestyle factors such as getting enough sleep (7-8 hours), regular exercise (especially strength training), managing stress to lower cortisol, and limiting alcohol consumption are all crucial for healthy testosterone levels.

For better hormonal health, opt for nutrient-dense foods such as fatty fish, eggs, leafy green vegetables, oysters, and healthy fats from sources like avocado and olive oil.

Yes, enjoying a donut in moderation as an occasional treat is acceptable. The main concern for hormonal health comes from chronic, frequent consumption of high-sugar, processed foods.