We will start our “Know Your Body” series with hormones. Why? Well, they are mostly misunderstood and they affect all of us. So, we want to bust the myths and help you to understand them more. Hormones, at their basic level, are chemical messengers that coordinate different functions in the body. They are produced from several glands, organs and tissues, medically known as the endocrine system.

There are over 50 different types of hormones in the human body that all serve a different and very important purpose. In this series, we will focus on some of the systems that hormones coordinate. Let’s get into it!

MetabolismA breakfast of eggs and coffee on a bed

Metabolism is the chemical (metabolic) process that converts the foods and drinks we consume into energy.

The body uses about one-tenth of its energy to convert the food that we eat into fuel. The remaining energy fuels your physical movement.

Metabolism and metabolic problems often get blamed for weight struggles. Our metabolism naturally regulates itself to meet our body’s needs. It is rare that metabolism is the cause of people’s weight gain or loss. 

The fact remains that anyone who burns more calories than they take in will lose weight. However, nutrition planning can help you to ensure that you’re eating the right stuff.

A fast metabolism simply refers to someone with an accelerated basal metabolic rate (BMR) which means the body burns a lot of calories, even when at rest. A slow metabolism means that the body needs fewer calories to keep it going. A fast metabolism does not necessarily lead to being thinner. In fact, studies have shown that people who are overweight often have fast metabolisms, which means their bodies need more energy to keep their basic day-to-day body functions going.


Homeostasis refers to the body’s need to reach and maintain a certain state of equilibrium.

Homeostasis is the body’s tendency to monitor and maintain internal states. When the level is off, such as your blood pressure, blood sugar regulation, fluid and electrolyte balance or body temperature, homeostasis will work to correct it. For example, to regulate temperature, you will sweat when you get too hot or shiver when you get too cold.

Sleep-Wake Cycle

Nearly every hormone in the body is released in response to our circadian rhythm, also known as the sleep-wake cycle.

Melatonin controls sleep patterns and tells your body when to get to sleep. Human growth hormone is released during deep sleep hours, which is vital to cell growth and repair.

In the early morning, your body’s cortisol production naturally surges and helps us to get up and go. This is often referred to as the cortisol awakening response. Once you’ve woken up the cortisol surge continues for around 30-45 minutes before returning to its baseline after an hour or so. If you are waking up tired every morning you are probably not getting enough sleep, or your circadian rhythm is disrupted. Not meeting your sleep needs means your body isn’t given ample time to curb cortisol secretion, leading to elevated daytime levels of cortisol.

As long as there is insufficient sleep, your body remains stranded in the fight-or-flight state. 

The long-term effects of sleep insufficiency have been studied widely and documented in scientific literature, particularly in the form of metabolic health issues such as:

  • Obesity
  • Weight gain
  • Type 2 diabetes
  • Heart disease
  • Getting adequate sleep is important for regulating several hormones, including:
  • Cortisol
  • Estrogen and progesterone
  • Hunger hormones, like insulin, leptin, and ghrelin
  • Melatonin
  • Thyroid hormones
  • Growth hormones

Growth and Development

A man reading a book

The main player in growth and development is the growth hormone. Produced by the pituitary gland, it has many functions including maintaining normal body structure and metabolism.

Growth hormone levels are increased by sleep, stress, exercise, and low glucose levels in the blood and have been linked to a sensation of wellbeing, specifically energy levels. There is evidence that 30-50% of adults with Growth hormone deficiency feel tired to a level that impairs their wellbeing.

The hormones concerned with growth are the pituitary growth hormone, thyroid hormone, the sex hormones testosterone and oestrogen, and the pituitary gonadotropic (sex-gland-stimulating) hormones.


Dopamine and serotonin are chemical messengers, or neurotransmitters, that help regulate many bodily functions. Dopamine is involved in movement, coordination, and feelings of pleasure and reward with serotonin involved in emotions as well, but it also affects digestion and metabolism.

Dopamine and serotonin are often called happy hormones. There are several hormones that play a role in our mood, however, these two are the most common. Dopamine plays an integral role in the reward system, a group of brain processes that control motivation, desire, and cravings. It also is the brain’s pleasure and reward centre, and it drives many behaviours and habits.

Alternatively, in addition to aiding digestion, serotonin is involved in regulating the sleep-wake cycle, mood and emotions, metabolism and appetite, cognition and concentration, hormonal activity, body temp and blood clotting. Low levels of serotonin have also been linked with mood disorders, such as depression and anxiety.

Dopamine and serotonin also have opposite effects on appetite; while serotonin suppresses appetite, low levels of dopamine can stimulate hunger. However, both dopamine and serotonin can impact mental well-being. Having too much or too little dopamine and serotonin can impair communication between neurons. This may lead to or indeed exacerbate the development of physical and mental health conditions.

Although dopamine alone may not directly cause depression, having low levels of dopamine may cause specific symptoms such as:

  • Lack of motivation
  • Difficulty concentrating
  • Feelings of hopelessness and helplessness
  • Loss of interest