Article  By Rosemarie Cianci, dietetics student in McGill’s School of Human Nutrition

There is a lot of talk about hormones and their role in weight loss. Leptin is one of those, so we’ll dive right in!

What is it?

Leptin is a hormone that is secreted by fat cells when you eat certain foods and regulates hunger and fullness cues. It reacts to your body’s insulin following the intake of food items. From there, it provides information to the brain about nutrition status. It regulates body weight by decreasing food intake and increasing energy expenditure. It makes you feel full and also allows the body to burn more calories!

What does it do?

Certain foods stimulate the release of leptin more than others. For example, consuming sugars such as sucrose and glucose will cause insulin levels to increase and leptin to be released. However, fructose, which is often found in the form of high fructose corn syrup, does not trigger the release of leptin. Therefore, when you drink foods that are high in HFCS, such as candy and soft drinks, leptin is not released and the body does not receive the signals to decrease food intake. You end up eating more!

What is leptin resistance?

Leptin resistance occurs when the body does not respond to levels of leptin and does not signal fullness. This often occurs in those who are overweight or obese as they have more fat cells and therefore produce more leptin. Despite the high production, the brain does not receive the signal from leptin and it is blocked.

Leptin resistance and the lack of regulation may explain why some people have a more difficult time losing weight than others. Their brain may not be receiving the signals of fullness and increased energy burning compared to others!

Can it be supplemented?

The current recommendation is that taking a leptin supplement is not effective when compared to the body’s production. For those who have resistance, even supplements of leptin will not work because their brain does not receive signals from the hormone in any way, whether by pill or from the body’s production.

However, more studies are currently being undergone in this field and this is something that may be on the horizon. A review from 2019 showed that leptin’s mechanism of action is still being discovered and this can hopefully improve the efficacy of leptin as a treatment of obesity.

Overall, there is currently not enough research to note that leptin supplements are safe and effective for weight loss. However, since fructose blocks the production of leptin, it may be a beneficial idea to limit sources of the sugar, especially high-fructose corn syrup-containing foods such as candy and soft drinks.

 

References:

https://www.mdpi.com/2072-6643/11/11/2704

https://www.nature.com/articles/0802753?proof=t

https://www-ncbi-nlm-nih-gov.proxy3.library.mcgill.ca/pmc/articles/PMC7765993/

https://www.frontiersin.org/articles/10.3389/fendo.2021.585887/full