When it comes to weight loss and body composition, how many calories we consume is only one part of the picture.
Calorie intake, hormones and metabolism are all interconnected factors that can impact weight loss.
Hormones play a critical role in regulating metabolism by controlling the storage and utilisation of energy.
In this blog post, we will explore the role of several hormones in regulating metabolism and weight loss, including thyroid hormones, insulin, leptin, ghrelin, cortisol, catecholamines and sex hormones.
Let’s have a closer look at these hormones:
1. Insulin. Insulin is produced by the pancreas and regulates blood sugar levels. When you eat, carbohydrates are broken down into glucose, which is absorbed into the bloodstream. In response, the pancreas releases insulin, which signals cells in the liver, muscle, and fat tissues to take up glucose from the blood and use it for energy or store it for later use.
Insulin is the only hormone that lowers blood sugar levels.
If blood sugar levels remain consistently high due to a diet high in sugar and refined carbohydrates, the body can become resistant to insulin.
2. Thyroid Hormones. The thyroid gland produces two main hormones: thyroxine (T4) and triiodothyronine (T3). These hormones regulate the body's metabolic rate, which is the rate at which the body burns calories and produces energy. When thyroid function is impaired and thyroid hormone levels are lower, the metabolism slows, burning fewer calories at rest as well as during exercise. Impaired thyroid function can lead to increased insulin resistance, leading to weight gain.
3. Leptin. Leptin is produced by adipose (fat) cells that helps regulate energy balance by controlling hunger and satiety. Leptin levels rise with increasing fat mass and signal the brain to reduce food intake and increase energy expenditure. In individuals who are overweight or obese, leptin levels can become chronically elevated, leading to leptin resistance and a reduced ability to feel full. Leptin resistance can be reversed by reducing sugar intake, eating a low inflammatory diet, regular exercise and getting good quality, restorative sleep.
4. Ghrelin. Ghrelin is produced by the stomach. It stimulates appetite and promotes fat storage. Ghrelin levels typically rise before meals and decrease after eating, but in individuals who are overweight or obese, ghrelin levels may remain elevated even after eating, leading to overeating and weight gain. Ensure you are eating adequate protein to promote healthy ghrelin levels and regulate hunger.
5. Cortisol. Cortisol is produced by the adrenal glands. It is often referred to as the “stress hormone”. It plays a key role in the body's "fight or flight" response, which is the body's natural response to perceived danger. Cortisol helps to mobilise energy reserves and increase blood sugar levels in order to provide the body with the energy it needs to respond to a stressful situation. Chronically elevated levels of cortisol can stimulate the production of glucose, which can lead to increased insulin resistance and fat storage, particularly in the abdominal region. In addition, elevated cortisol levels can interfere with sleep quality and quantity, which can impact metabolism and increase hunger and appetite.
You can regulate cortisol levels by doing things that relieve your stress: exercise, walk in nature, take a bath, read a book, listen to music, sing, practice mindfulness, meditation, yoga and get enough sleep.
6. Catecholamines. Catecholamines, including adrenaline and noradrenaline, are hormones produced by the adrenal glands. They are released in response to stress or exercise, leading to an increase in energy expenditure and fat burning. Adrenaline levels rise in response to acute stressors, such as fear or excitement, and promote the mobilisation of energy stores to provide energy for the stress response. Adrenaline also stimulates the breakdown of glycogen in the liver and muscle, leading to increased blood glucose levels.
7. Sex Hormones. Sex hormones, such as estrogen, progesterone and testosterone, can have an impact on metabolism and weight. These hormones play a role in regulating body composition and metabolism, but their effects can vary depending on the individual's sex and hormonal balance.
- Oestrogen and progesterone influence fat burning or fat storage
- Testosterone can help to increase muscle mass and decrease body fat, which can lead to faster metabolism and a leaner body composition.
(My next blog post will explore changes in weight and metabolism when the female sex hormone levels start to change in midlife/menopause)
When your hormones are in balance, your blood sugar levels are regulated and your need and desire to consume more calories is dialed down. However, when these hormones are not balanced, we can see the effects in changes in sleep, hunger, mood, energy and cravings. Hormonal imbalances can lead to weight gain, mood changes, and other health problems.
Maintaining stable blood sugar levels through a balanced diet, regular exercise, stress management, good quality sleep and proper hydration is crucial for regulating metabolism and promoting weight loss.
Do you feel hungry all the time? Does your energy fluctuate throughout the day? Are your struggling to manage your weight? Do you want to work on your body composition?
Book in for a Free 10 minute Discovery Call to find out how I can help.