Intermittent fasting, or fasting periodically for specific periods, has grown in popularity because of its many benefits for weight loss and overall health.
This article explores the relationship between intermittent fasting and testosterone levels, offering insight for practitioners and patients to determine if this fasting meal plan is right for them.
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What is Intermittent Fasting?
Intermittent fasting involves not eating food for some time, though you can drink water, black coffee, or unsweetened tea during the fast. Numerous methods of intermittent fasting exist, including:
- 16/8: Eat only during an 8-hour window and fast for 16 hours daily
- 5:2: Eat regular meals five days weekly. Limit food intake to one 500-600-calorie meal daily for two days per week
- Eat-stop-eat (24-hour fast): Fast for 24 hours once or twice per week
- Alternate-day fasting: Consume a normal meal plan one day and fast or eat one small meal (containing 500 calories or less) the next day
After several hours without food, the body exhausts stored sugar energy and burns fat instead. This is beneficial for various reasons, particularly for individuals desiring weight loss and healthy weight maintenance.
It's important to consult with a healthcare provider before beginning any fast, especially for individuals who take medications or have an illness, injury, or disease.
Furthermore, going longer than 24 hours without food could be dangerous or cause the body to store additional fat after transitioning to starvation mode. It might take several weeks before a fasting individual becomes accustomed to this diet.
However, the human body is designed to withstand periods without food, as people sometimes fast for several days in prehistoric times when they hunted and gathered for food to survive.
What Are the Potential Benefits of Intermittent Fasting?
Studies have shown that the potential benefits of intermittent fasting include:
- Weight loss
- Reduced body fat
- Improved fitness levels
- Enhanced glucose metabolism
- Better insulin sensitivity
- Less oxidative stress
- Reduced inflammation
- Lower risk of chronic diseases
- Improved obesity-related disease management
- Reduced cholesterol and blood pressure
- Improved memory and thinking
- Healthier heart
- Stronger immune system
However, side effects of intermittent fasting reported in research are fatigue, headaches, mood swings, dizziness, and excessive urination. Fasting may also affect testosterone and other hormone levels.
Understanding Testosterone
Testosterone, often called the male sex hormone, is an essential hormone both men and women need in balanced amounts for optimal sexual function and the maintenance of muscle mass, energy levels, mood, fetal development, sex drive, and more.
Various factors influence testosterone production and hormone balance, such as age, diet, exercise, lifestyle, stress, tumors, steroid use, and underlying medical conditions. Maintaining hormonal balance is the best way to optimize energy and essential body functions while avoiding side effects.
How Intermittent Fasting Affects Testosterone
Studies demonstrate that intermittent fasting can affect testosterone. Many of the studies below show decreases in testosterone after intermittent fasting, though diet-induced weight loss can help balance testosterone and other hormones in overweight and obese individuals.
- One study found that while fasting didn’t affect estrogen in women, intermittent fasting reduced testosterone levels in physically active, lean young men. The researchers determined that while the lowered testosterone levels didn't negatively affect muscle mass and strength, low T could affect metabolic health and libido.
- Another study showed that time-restricted eating for 12 months reduced body weight and fat mass, less inflammation, improved insulin sensitivity and lipid profiles, and reduced testosterone levels. The researchers concluded that long-term intermittent fasting and resistance training can reduce inflammation, heart disease, and risk of metabolic disease.
- A third study suggests that men's testosterone concentration was significantly reduced after intermittent fasting for nine days.
- A fourth study found that intermittent fasting decreased testosterone by 10% in women with polycystic ovary syndrome (PCOS).
- Research also shows that resistance-trained men who followed the 16/8 intermittent fasting diet had significant reductions in testosterone levels.
- However, one review reports that intermittent fasting had no significant effect on hormone levels, including testosterone.
- Other researchers demonstrated that testosterone levels did not change in premenopausal and postmenopausal women who intermittently fasted.
However, if intermittent fasting helps overweight or obese individuals achieve healthier body weights with reduced central fat accumulation, fasting may help boost low testosterone levels over time.
- For example, researchers suggest that weight loss can increase testosterone levels in obese men.
- Regular exercise also optimizes testosterone production and hormone balance.
The mechanisms by which intermittent fasting affects testosterone production are not entirely clear, but it is related to its impact on overall calorie reduction and weight management.
Fasting could decrease testosterone in normal-weight men. However, intermittent fasting that causes weight loss may boost long-term testosterone production in the overweight population.
Benefits of Intermittent Fasting-Induced Weight loss
The benefits of balanced testosterone due to healthier weight management caused by intermittent fasting include:
Physical Health
Examples of physical health benefits stemming from balanced testosterone include more muscle mass, less body fat, more energy, improved sexual functioning, and a stronger sex drive. Maintaining ideal testosterone levels can also reduce or delay age-related hair loss.
Mental Health
Hormone balance can also maximize mental health. It helps improve mood, reduce depression, boost motivation and self-confidence, and enhance cognitive function – including concentration and memory.
Reproductive Health
Maintaining ideal testosterone balance is critical to optimal libido and fertility in men and women.
Considerations
However, avoid extreme fasting and understand that the benefits of fasting on testosterone are highly linked to healthy weight management, not necessarily fasting alone. If your testosterone levels and body weight are within a normal range, fasting may not be needed or beneficial.
Practical Guidelines for Intermittent Fasting
Use the following guidelines to choose a personalized intermittent fasting method based on lifestyle, medical history, and health goals.
Choosing the Right Method
Individuals should consult with a healthcare provider before trying intermittent fasting, especially if they have diabetes or other chronic diseases, develop medical concerns, or take medications. Intermittent fasting strategies should be based on individualized needs and preferences, as there are an array of fasts to choose from.
Starting Out
A simple intermittent fasting step-by-step guide for beginners is as follows:
- Talk with a provider about which safe intermittent fasting method is best for you.
- To begin with, try an easy-to-follow fasting method, such as eating only from 10:00 a.m. to 6:00 p.m. Alter this 16/8 fast with a 5:2 or more restrictive fasting regimen if you’re up for it and your health care provider endorses it.
- Track any side effects, such as fatigue, headaches, or dizziness, and report them to your healthcare provider.
It’s also helpful to routinely track blood pressure, cholesterol, body weight, and hormone levels to ensure they remain within ideal ranges.
Diet and Nutrition
Foods to consume that support natural testosterone production, because they are whole, nutritious foods rich in zinc, fiber, heart-healthy fats, or other testosterone-enhancing nutrients, include:
- Fruits
- Vegetables
- Green tea
- Nuts
- Seeds
- Flax seeds
- Whole grains
- Legumes
- Grass-fed, organic meats
- Wild-caught seafood
- Eggs
- Fish
- Extra virgin olive oil
- Other plant oils
- Avocados
Studies show that a low-carb Mediterranean diet rich in vegetables, fish, and olive oil helps increase testosterone levels.
Foods to limit or AVOID to promote hormone balance because excess intakes can disrupt hormone levels include:
- Processed meats
- Fatty cuts of non-organic meats
- Fried foods
- Refined grains (white rice, white bread, baked goods, etc.)
- Added sugars
- Sugar-sweetened drinks (sodas, sweet tea, etc.)
- Excessive amounts of caffeine
- Food dyes
- Highly processed foods
- Excessive dairy foods
- Alcohol
Poor nutrition can contribute to imbalanced hormones and numerous disease risk factors. It can also promote obesity, a potential hormone disruptor linked to reduced testosterone levels.
Hydration and Supplements
Regardless of your diet, it is important to stay hydrated by drinking plenty of water or other calorie-free drinks like coffee or tea.
Supplements to consider for better testosterone balance in individuals with low testosterone include zinc, quercetin, DHEA, and grape seed extract.
Potential Risks and Considerations
While fasting provides various physical and mental health benefits, potential risks and other considerations exist.
Medical Conditions
Intermittent fasting isn’t for everybody, including pregnant and nursing women, children, teenagers, people with type 1 diabetes taking insulin, and individuals with a history of eating disorders. Check with your doctor if you have gastroesophageal reflux disease (GERD), kidney stones, type 2 diabetes, or other chronic conditions to determine which diets are the safest.
Side Effects
Intermittent fasting can cause potential side effects, including:
- Fatigue
- Hunger
- Nausea
- Insomnia
- Headaches
- Dizziness
- Weakness
- Low blood sugar
However, these or other effects typically disappear within one month of beginning a fasting regimen and aren’t as severe when choosing less-restrictive fasts. To mitigate side effects, start with a minimally-restrictive form of fasting, such as the 16/8 plan.
Consultation with Healthcare Providers
It’s important to consult with a healthcare provider before beginning intermittent fasting to determine which type of fast, if any, is best suited for your personalized needs.
Real-Life Success Stories
Relevant case study success stories involving intermittent fasting include reports of weight loss and improved health outcomes, such as enhanced blood sugar management, total cholesterol, and blood pressure.
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Key Takeaways
- Intermittent fasting provides various health benefits, including healthy weight management, reduced body fat, better insulin sensitivity, less inflammation, and a lower risk of chronic diseases.
- Fasting can enhance hormone balance in some people because of its effects on healthy weight management.
- However, research shows that intermittent fasting often decreases testosterone levels in physically active, lean young men; but its effects on weight loss can promote hormone balance in overweight men and women.
- Consume non-processed, nutrient-rich, whole foods to optimize testosterone production.
- Other diets, such as organic, low-carb, Mediterranean diets, contribute to healthy weight management and testosterone balance, so consider them if your testosterone levels need a boost.
- Share any experiences with intermittent fasting and its effects on testosterone, and consult with a healthcare provider before trying intermittent fasting, particularly if you take medications or have been diagnosed with an illness or disease.
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