Know your fat-loss hormones

When it comes to fat loss, there are more players in the game than just calories and exercise. Numerous hormones are at play in this frustrating saga of excess body fat, including; insulin, cortisol, leptin, and oestrogen.


The first hormone to understand when it comes to fat loss is insulin. When we eat something containing sugar, e.g. bread, sweet food, rice, potatoes, pasta, processed foods or foods from packets, these foods are converted into glucose in our blood. This causes a spike in blood sugar levels, which triggers the pancreas to secrete a hormone called insulin. Insulin’s role is to bring our blood sugar levels back into a safe range. In order to do this, it needs to get rid of the glucose in our blood by shipping it off to our cells to be stored in our muscles for future energy, or our adipose tissue as fat. This means that by eating a diet that largely consists of food that spikes our blood sugar, we directly inhibit fat loss.

Insulin Resistance (IR) has an even greater effect on the inability to lose weight. Insulin Resistance is largely common in Western societies and occurs when insulin receptor sites have become desensitised to insulin, causing an even greater production of insulin and glucose. IR is caused by a poor diet of processed foods, refined flours and sugars, and excess caffeine, as well as an insufficient nutrient intake. Another important element about IR is that it increases the production of cortisol.


Cortisol’s role is to help the body resist long-term stress. This hormone is produced by the adrenal glands and is secreted when we experience situational or emotional stress. Cortisol causes an increase of glucose in the blood, which spikes blood sugar levels. Traditionally, this occurs to help the body get out of a dangerous (stressful) situation, e.g. run away. However, in our day and age stress is usually due to work, family, relationships, and money, not events that require us to flee. In this way, cortisol has a similar response to insulin; it causes us to gain weight and makes fat loss difficult. When we experience stress on a daily basis our bodies continue to produce excess glucose, which makes fat loss near impossible. Stress management is crucial for fat loss. Cortisol also has a secondary effect of desensitising our cells to other hormones, e.g. cortisol impairs leptin signalling.


Leptin is a hormone that suppresses appetite after the body has received enough energy and nutrients and it also increases our energy expenditure. Asides from cortisol, leptin is suppressed by a consuming excess sugar. This means that a modern diet of refined flours and sugars, excess fruit, and processed foods will also deregulate leptin, causing increased appetite. To support leptin function, consume a nutrient-dense diet consisting of plenty of vegetables, quality fats, fish, moderate protein, nuts, and legumes.


Oestrogen is a sex hormone, most prominent in women, and contributes to reproduction, bone growth, and cardiovascular health. However, when in excess, oestrogen also works to increase body fat. Why would someone have excess oestrogen? Consuming foods containing oestrogen, e.g. soy, can increase oestrogen levels. Using plastic containers or drink bottles containing BPA can increase oestrogen due to their xenoestrogens properties. Lastly, a diet consisting of sugars, refined carbohydrates, processed foods, alcohol, and caffeine increases our oestrogen levels substantially by congesting the liver. When the liver is congested with these external toxins, detoxification is impaired, and oestrogen is recycled. However, the ovaries continue to produce new oestrogen, and alongside the recycled oestrogen, the body experiences an excess of this hormone. This leads to increased fat accumulation, making weight loss difficult.

So what should I do?

To support fat loss, consume a wholefoods diet of fish, meat, eggs, vegetables, fruits, nuts, unprocessed dairy, and legumes. Support the liver and manage blood sugar levels by avoiding sugars, refined carbohydrates, processed foods, and foods from packets.

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