The Influence of Diet and Lifestyle on Hormones by Dr. Sarah Schenker

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Hormones are your body’s chemical messengers. They help control practically every physiological process in your body, including your metabolism, immune system, menstrual cycle, appetite and mood. A precise hormonal balance is vital to proper body functioning. A poor diet can lead to unbalanced hormones through excessive amounts of unhealthy fats and sugar and through low intakes of essential nutrients such as essential fats, vitamins and minerals.

Conversely, being well nourished and eating balanced diet can help to restore hormonal balance.

The symptoms of hormonal imbalance are wide ranging and include more common symptoms like weight gain and fatigue, but also lesser known problems like hair loss, skin problems and heart palpitations.

To better understand the influence of diet composition on hormones, we should consider the groups of hormones that are responsible for different functions in the body.

Female hormones

Oestrogen is the primary female sex hormone which regulates  the menstrual cycle and prepares the uterus for pregnancy. Oestrogen production depends on adequate intakes of various nutrients including protein, omega 3 fats, magnesium and B vitamins. Low intakes of these nutrients through poor eating habits can affect oestrogen production and may cause periods to stop, even in young women, poor bone health and low mood. For older women experiencing the  perimenopause, the time period that precedes menopause, oestrogen levels may fluctuate wildly causing mood swings and weight gain. During the menopause fluctuations and subsequent drop in oestrogen levels lead to the characteristic symptoms of menopause. These include hot flashes, night sweats, mood changes, and menstrual irregularity.

Oestrogen is also influenced by other hormones in the body, some hormonal imbalances can lead to oestrogen dominance, or extreme fluctuations that can cause the following problems:

  • Irregular or absent periods: Increasing irregularities in periods signal a disruption in the hormonal activity that controls menstruation. Often, the cause is an imbalance between oestrogen and progesterone due to the strong effects of the stress hormone, cortisol.
  • Weight gain: Changes to weight or body shape are caused by shifting hormones, particularly in the menopause, that lead to excessive fat storage in the abdomen. This can occur even in women who have never experienced weight problems before. High levels of stress and poor sleep increase fat around the abdomen that can be difficult to lose.
  • Irritability and/or moodiness: Feeling out of control or overwhelmed can be caused by sudden changes in the balance of oestrogen, testosterone and progesterone or from adrenal stress imbalances.
  • Skin issues: Adult acne is associated with polycystic ovarian syndrome (PCOS), a hormonal condition that also causes irregular or absent menstrual periods due to ovulation irregularities.
  • Hair loss or unusual growth: Imbalances in thyroid function or between oestrogen and testosterone can cause thinning hair, and high levels of testosterone (such as in PCOS) can lead to unusual hair growth, including on the face.
  • Infertility: Women with PCOS often have high amounts of androgens (including testosterone) as well as insulin resistance. Both contribute to increased oestrogen, along with lack of ovulation and infertility.

While oestrogen can’t be obtained from the diet, various plant foods contain phytoestrogens. These are groups of chemicals that weakly act like oestrogen in the body helping to balance out either excessive or low levels. Eating foods that are rich in phytoestrogens may help relieve some menopause symptoms as well as help lower your risk of some conditions associated with menopause.

Soy is the richest dietary source of phytoestrogens. It’s particularly rich in a type of phytoestrogen called isoflavones. The isoflavones in soybeans bind to oestrogen receptors in the body. There have been hundreds of studies on isoflavones and soy, with conflicting results. However, according to a recent review, there’s substantial evidence that soy foods may help you address several conditions associated with menopause, such as lowering the risk of ischemic heart disease, improving blood cholesterol levels, and relieving hot flashes.

Flaxseed is another significant source of phytoestrogens. It specifically contains a type of phytoestrogen called lignans. Like the isoflavones in soy, lignans have both an oestrogenic and antiestrogenic effect, although to a much lesser degree.

Metabolic hormones

Insulin is a hormone produced by the pancreas, secreted in small amounts throughout the day and in larger amounts after meals.

Insulin allows cells to take in blood sugar for energy or storage, depending on what is needed at the time.

Insulin is also the main fat storage hormone in the body, signalling fat cells to store fat, and suppressing fat breakdown.

Being overweight and poor eating habits (in particular excessive consumption of sugar and refined carbohydrates) can lead to cells becoming resistant to insulin. When cells are insulin resistant, both blood sugar and insulin levels go up significantly. Chronically elevated insulin levels can lead to a number health problems, including worsening obesity, metabolic syndrome and type 2 diabetes.

In order to normalize insulin levels and improve insulin sensitivity:

  • Avoid or reduce sugar intake: High amounts of fructose and sucrose promote insulin resistance and raise insulin levels.
  • Balance carbohydrate and protein at meals: A lower carbohydrate, higher protein intake can cause an immediate drop in insulin levels.
  • Include plenty of healthy fats: Omega 3 fats found in fatty fish can help lower fasting insulin levels.
  • Exercise regularly: Research shows that regular cardiovascular activity such as brisk walking or jogging can improve insulin sensitivity.
  • Ensure magnesium intake is adequate: Poor magnesium intakes and low magnesium status is associated with poor insulin sensitivity.

Thyroid hormones

Thyroid hormones help control growth, cell repair, and metabolism. As a result, people with low levels of thyroid hormones may experience tiredness, hair loss, weight gain, feeling cold, and a low mood.

A combination of the right nutrients can ensure healthy thyroid function and reduce symptoms.

Thyroid hormones have an important role in the regulation of metabolism rate. The faster a person’s metabolism, the more energy (calories) they will burn. If thyroid hormone levels are disrupted through a lack of nutrients   the slower the metabolic rate and fewer calories are expended at rest. This can make weight gain inevitable and weight loss difficult and frustrating.

Research shows that moderate to high intensity aerobic exercise may help boost thyroid hormone levels, which in turn, helps to increase metabolic rate. Research also shows that higher protein diets help increase metabolic rate.

Several nutrients are important for optimal thyroid health.

  • Iodine is an essential mineral that’s needed to make thyroid hormones. Poor intakes of iodine are common and affects nearly one in three people. Iodine rich foods include seaweed, fish, dairy, and eggs.
  • Selenium has an important role in activating thyroid hormones so they can be used by the body. This essential mineral also has antioxidant benefits, which means it may protect the thyroid gland from oxidative damage. Selenium rich foods include Brazil nuts, tuna, sardines, eggs, and legumes.
  • Zinc also has a role in regulating thyroid hormones and although zinc is fairly ubiquitous in foods, a poor diet or extreme dieting to lose weight can lead to low intakes which can impact on thyroid function.

Stress hormones

Cortisol is a stress hormone released by the adrenal glands. It has an important role in helping the body deal with stressful situations, the brain triggers its release in response to many different kinds of stress.

However, when cortisol levels are too high for too long, it can lead to many health problems. Over time, high levels may cause weight gain and high blood pressure, disrupt sleep, negatively impact mood, reduce your energy levels and contribute to diabetes.

Research has shown that cortisol increases appetite and signals the body to shift metabolism to store fat. It interferes with daily cycles of other hormones, disrupting sleep patterns and causing fatigue. Cortisol interferes with memory, contributing to mental cloudiness or “brain fog”. It also  hampers the immune system, making you more prone to infections.

Regular exercise and a good sleep pattern are critical in helping to regulate cortisol production. A healthy diet is also key. A high sugar intake is one of the classic triggers for cortisol release. Regular, high sugar intakes may keep cortisol levels elevated. Whereas probiotics, prebiotics and omega 3 fats have all been shown to reduce cortisol. Staying well hydrated is also important in controlling cortisol, as dehydration increases cortisol.

Mood influencing hormones

Serotonin acts as a mood stabilizer, it is needed for healthy sleeping patterns and to boost mood. Research shows that shows that serotonin levels can have an effect on mood and behaviour.

Serotonin is derived from the amino acid tryptophan and it is known that tryptophan depletion is seen in those with mood disorders such as depression and anxiety. Foods that have been shown to help increase serotonin levels include eggs, turkey, cheese, salmon and nuts and seeds.

The conversion of tryptophan to serotonin relies on vitamin B6, so if levels are low, production of serotonin can be reduced.

Melatonin is a hormone that is produced by the pineal gland in the brain and then released into the bloodstream. Darkness prompts the pineal gland to start producing melatonin while light causes that production to stop. As a result, melatonin helps regulate circadian rhythm and synchronize our sleep-wake cycle with night and day. In doing so, it facilitates a transition to sleep and promotes consistent, quality rest. Magnesium is needed for the production of melatonin and poor intakes, which are common in many women, can reduce melatonin production.

Appetite hormones

Leptin, known as the satiety hormone, is produced by fat cells to reduce appetite and cause feelings of being full. Iits role is to communicate with the hypothalamus, the portion of the brain that regulates appetite and food intake. Leptin tells the brain that there’s enough fat in storage and no more is needed, which helps prevent overeating.

Obese people are often leptin resistant as the leptin system doesn’t work as it should. When leptin signalling is impaired, the message to stop eating doesn’t get through to the brain, so it doesn’t realize you have enough energy stored. Leptin levels are also reduced when a person loses weight, which is one of the main reasons it is so hard to maintain weight loss in the long-term.

Two potential causes of leptin resistance are chronically elevated insulin levels and inflammation in the hypothalamus. To avoid leptin resistance it is important to avoid inflammatory foods such as excessive sugar consumption and foods that contain trans fats, particularly deep fried foods.

Omega 3 fats can help to improve leptin sensitivity as does regular exercise and a healthy sleep pattern.

Ghrelin is known as the hunger hormone. When th steomach is empty, it releases ghrelin, which sends a message to the hypothalamus to stimulate appetite

Normally, ghrelin levels are highest before eating and lowest about an hour after had a meal has been consumed. However, in overweight and obese people, fasting ghrelin levels are often lower than in people of normal weight. Studies have also shown that after obese people eat a meal, ghrelin only decreases slightly. Because of this, the hypothalamus doesn’t receive as strong of a signal to stop eating, which can lead to overeating .

Research has shown that to improve the function of ghrelin it is recommended to avoid high-fructose corn syrup and sugar-sweetened drinks, which can impair ghrelin response after meals. It is also important to include a good source of protein at every meal, especially breakfast, as this will reduce ghrelin levels and promote satiety.


At every age, hormones are fluctuating on a daily basis, in mostly predictable patterns. However, dramatic fluctuation can lead to unpleasant symptom and health problems. Some of these dramatic fluctuations occur naturally, such as puberty, pregnancy or menopause, but sometimes they can be the result of poor eating habits and diet, stress, inactivity and poor sleep. As an imbalance worsens, symptoms can multiply, or their severity and frequency can increase.

Improving your diet and changing your eating habits, along with regular exercise and a good sleep pattern can help to get back to a state of hormonal equilibrium, better health and a sense of wellbeing.
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