How Different Diets Influence Your Hormones

Hormones are chemical messengers that the glands of your endocrine system produce. These glands include the testicles, ovaries, and adrenal glands.

Hormones control many processes within your body, including blood sugar regulation, sex drive, fertility, metabolism, mood regulation, and more.

Several factors can affect your hormones, including age, underlying health issues, and diet. Following certain dietary patterns can positively or negatively affect your hormonal health.

The Mediterranean diet is a way of eating followed by people living along the coast of the Mediterranean Sea, including Italy, Greece, Spain, and southern France. It’s high in whole foods, such as vegetables, fruits, fish, and legumes, and is low in ultra-processed foods.

May Improve Testosterone Levels

Studies show that the Mediterranean diet impacts testosterone levels in both men and women. 

A small study that included 50 men with reduced fertility found that after three months of following a low-carbohydrate, organic, Mediterranean diet, the men’s testosterone levels significantly increased compared to baseline.

The Mediterranean diet may also be effective for increasing testosterone levels in elderly men. This is significant as testosterone levels tend to decrease as men age.

It may also help reduce testosterone levels in women. A small study on women with polycystic ovarian syndrome (PCOS) found that a 12-week low-carbohydrate Mediterranean diet significantly reduced testosterone levels compared to a low-fat diet.

May Lower Estrogen Levels

The Mediterranean diet has been linked to a lower risk of estrogen-related cancers, such as breast cancer. 

The Mediterranean diet is high in fiber, which increases the amount of estrogen the body removes through stool. It’s also high in antioxidants like flavonoids, which may reduce estrogen. Reduced estrogen levels lower the risk of cancers associated with high estrogen levels.

A research review found that following a Mediterranean-style diet was strongly associated with lowering harmful forms of estrogen and preventing breast cancer development in postmenopausal women.

May Lower Cortisol Levels

A recent study found that people who followed either a traditional Mediterranean diet or a Green Mediterranean diet (more plant-based Mediterranean diet) for 18 months had significantly reduced fasting morning cortisol (FMC) levels compared to people following a healthy diet based on recommended dietary guidelines.

Both Mediterranean diets were low in calories, lower in carbohydrates than the traditional healthy diet, and included 28 grams of walnuts per day. The Green Mediterranean diet also included 3-4 cups of green tea per day and a daily shake made with Wolffia-globosa Mankai, a high-protein aquatic plant.

The ketogenic or keto diet is an eating pattern that is very low in carbohydrates, high in fat, and contains moderate amounts of protein.

May Improve Testosterone Levels

Research suggests that the keto diet can increase testosterone levels in men and lower testosterone levels in women.

A research review found that both regular calorie-load and very low-calorie keto diets significantly increased total testosterone levels in men. However, the very low-calorie keto diets were more effective.

Another review of studies found that women with PCOS who followed ketogenic diets for 45 days or longer experienced significant improvements in reproductive hormone levels, including reduced testosterone levels.

Protein is a macronutrient necessary for body processes like immunity, muscle growth, and hormone production. You can find protein in animal and plant foods, such as meat, eggs, and beans.

May Improve Insulin Levels

A recent study found that diets high in either animal or plant protein may improve insulin resistance. 

In the study, people with prediabetes or type 2 diabetes followed one of two different low-calorie, high-protein diets. Both diets provided 35% of total calories from protein, with 75% of the protein coming from either plant-based or animal proteins. After six months, both diets had a similar beneficial effect on levels of fasting insulin and insulin resistance.

Another study compared a high-protein diet of 30% protein and 40% carbohydrates to a Mediterranean diet of 30% protein and 55% carbohydrates. The study found that the high-protein diet was more effective in reducing insulin resistance in women with obesity than the Mediterranean diet.

May Improve Hunger and Fullness Hormones

Protein is the most filling macronutrient, and some studies suggest increasing protein intake can reduce ghrelin and increase satiety hormones. However, research on the long-term effects of high-protein diets is limited.

A research review found that short-term protein intake decreased ghrelin and increased cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), another satiety hormone. However, the review also found that long-term high-protein intake significantly decreased GLP-1.

Plant-based diets include eating patterns that avoid or limit animal products like meat and dairy and prioritize nutrient-rich plant foods like legumes, grains, and greens.

May Improve Insulin Levels

Research has shown that plant-based diets high in fiber can help reduce insulin resistance and improve insulin sensitivity. 

A recent review found that, compared to control diets, following a plant-based diet for at least 14 days improved insulin sensitivity and reduced levels of fasting insulin in people who were overweight or obese. The beneficial plant-based diets in this review included:

• Vegan: The person eats no animal products, including meat, fish, eggs, and dairy.
• Ovo-vegetarian: The person eats eggs but no meat, fish, or dairy.
• Lacto-vegetarian: The person eats dairy but no meat, fish, or eggs.
• Lacto-ovo-vegetarian diets: The person eats eggs and dairy but no meat or fish.

Another study found that people who more closely followed a nutritious plant-based diet had lower fasting insulin levels than those who ate more animal-based foods.

Most people in the United States do not consume enough fiber, an indigestible nutrient found in plant foods like fruits, vegetables, legumes, and seeds. Fiber can help support digestion and gut health, and high-fiber diets have been linked to a lower risk of health conditions like type 2 diabetes, colon cancer, and heart disease.

May Improve Insulin Levels

High-fiber diets are a great choice for improving multiple aspects of health, including insulin resistance. Several studies have found that low fiber intake is associated with higher fasting insulin levels.

Because high fiber intake positively influences insulin and blood sugar levels, studies show that a daily fiber intake of over 25 grams in women and over 38 grams in men is associated with a 20-30% reduced risk of developing type 2 diabetes.

Fat is a calorie-dense macronutrient. Certain fats, such as saturated and trans fats, are considered worse for health because they raise low-density lipoprotein (LDL, or “bad”) cholesterol. Other types, like mono- and polyunsaturated fats, are considered better for health because they can lower LDL cholesterol.

A low-fat diet involves eating foods that have less than 30% of their calories from fat—or that contain 3 grams or less of fat per every 100 calories.

May Worsen Testosterone Levels

Low-fat diets may negatively impact testosterone levels. A research review found that, compared to high-fat diets, low-fat diets moderately decreased testosterone levels in men.

Men following low-fat diets have also been shown to have lower testosterone levels, even when controlling for factors like age, body weight, and activity levels. This could be because low-fat diets may decrease testosterone production in the testicles, though more research is needed.

The Western diet is a common North American diet high in ultra-processed foods, added sugar, and animal foods like red meat, dairy, and eggs.

May Cause High Estrogen Levels

Western-type diets are associated with high estrogen levels and an increased risk of estrogen-related cancers, including breast cancer.

A review found that a Western diet high in red and processed meat, high-fat dairy products, and sweets was associated with an 18% increased risk of estrogen-related breast cancers. The review also found that a nutritious diet high in fruits, vegetables, fish, and whole grains was associated with a 20% reduced risk of estrogen-related breast cancer.

May Worsen Hunger and Fullness Hormones

A Western diet high in ultra-processed foods, refined carbohydrates, and added sugar is linked to leptin resistance. When your body stops appropriately responding to leptin, a fullness hormone, it leads to high leptin levels, increased hunger, and reduced feelings of fullness.

Following a Western-type diet increases the risk of leptin resistance and is also linked to obesity. This may be because the Western diet increases inflammation in the hypothalamus, the area of the brain impacted by leptin.

Your diet can significantly affect your hormonal health, influencing hormones like estrogen, testosterone, insulin, cortisol, ghrelin, and leptin.

Following nutritious diets, such as Mediterranean, plant-based, and low-carbohydrate diets, can benefit hormonal health. However, eating Western-type diets high in ultra-processed food, refined grains, and added sugar can negatively affect your hormones.