What’s the Fuss about Leptin?


Picture this: It’s Thanksgiving Day. You have been looking forward to the delicious food that your family has prepared. As you sit at the extended table with your family, you start to feel like you haven’t had anything to eat in a week. After enjoying the lovely home cooked meal, your grandmother starts to roll out a delicious pumpkin pie, but now you are feeling more stuffed than your Thanksgiving turkey. But how can you go from feeling like you haven’t had anything to eat in a week to feeling like you don’t want to eat for a week?

It’s all thanks to the hormone called leptin. Leptin, otherwise known as the “satiety hormone” or “starvation hormone”, is a hormone that is produced by your body’s fat cells and helps to regulates your body weight. When an adequate amount of fat cells are present, leptin is released into the bloodstream and travels to the brain to tell the body that it doesn’t need to eat. Likewise, when there is an inadequate amount of fat cells present, leptin tells the brain that the body is hungry and needs food immediately. This is known as a negative feedback system, which helps the body maintain a balanced weight, (thanks homeostasis!).

But you may be thinking: “why is it that some people who have high body fat stores, continue to eat? Doesn’t their brain know that they have plenty of energy stores?” This is known as leptin resistance.

People with higher body fat stores also have higher levels of leptin. When high levels of leptin are continuously released by the fat cells, the brain is put in overdrive by the cascade of signals. Over time, the signals to the brain become disconnected. Ultimately, the brain thinks the body is hungry, and tries to do as much as possible to obtain food and conserve energy.

So how does one overcome leptin resistance? Maintaining a healthy diet low in processed foods, as well as exercising regularly and sleeping well is always a step in the right direction. Sustaining a healthy lifestyle can sometimes be difficult, and for good reason too! As your body begins to lose weight, body fat stores begin to decline. And as you lose more and more fat stores, you also lose leptin. This sets off the alarm bells in your body, making it think that it is in starvation mode, and making you feel hungry all the time! Needless to say, losing weight is easier said than done. Thus, it is important to set realistic goals to help maintain a sustainable lifestyle.

Bottom line: Leptin is a hormone released by our fat cells that helps maintain our body weight. Too much body fat can lead to leptin resistance, where the brain becomes unresponsive to the leptin’s signals. Living a healthy lifestyle can help keep your leptin levels in check and avoid the development of leptin resistance.

Blog post contributed by Alyssa Ramuscak, Nutrition & Dietetics Student, University of Western Ontario