Posted March 23, 2013 by Gareth Evans in Health

Leptin: The hormone with the key to effective weight loss

Chemical structure of leptin, a hormone secreted by fat cells that reduces appetite and that plays a role in the development of obesity.
Chemical structure of leptin, a hormone secreted by fat cells that reduces appetite and that plays a role in the development of obesity.

Weight loss is a complex beast. If reducing your body fat composition is you’re primary fitness goal, there are a wide range of factors that play a role in reducing your body fat percentage. These factors range from the make-up of your diet, through to what type of training you’re undertaking, how frequently you’re training, what time of day you are eating, how frequently you’re eating, and whether or not you are getting enough rest.

One factor that we have not discussed before, however, and something which could be keeping you from achieving the leanness you desire, is the level of leptin in your body.

What is leptin?

Leptin is, quite simply, the most important hormone in the human body when it comes to weight loss. And I’m guessing by the bemused look on your face, that you’ve never heard of it. Don’t worry, you’re not alone. But if you’re serious about getting lean, understanding how leptin can affect your body’s fat stores could make all the difference.

Leptin is a hormone which is naturally produced by the fat cells in the human body. The hormone is released into the bloodstream and is transported to the hypothalamus in the brain, where it suppresses the appetite and gives you that feeling of fullness.

How does leptin affect body fat composition?

While your goal may be to reduce body fat, some body fat is essential to the proper functioning of the human body. Leptin essentially helps the body to fully utilise fat stores. Through its role as a messenger to the brain, regarding hunger and energy levels, leptin tells the brain whether or not the body has sufficient fat stores. Low levels of leptin in the human body, therefore, can cause the body to store more fat, facilitated by a slowing of the body’s metabolic rate. If the body has sufficient leptin levels, then the body speeds up its metabolic rate, promoting weight loss.

In short, if weight loss and body fat reduction are your goals, you must work to ensure that your body produces the optimum amount of leptin.

The importance of eating a balanced diet

Diet is where most people who say that they are serious about getting lean fall down. They either refuse to commit to cleaning up their diet or, equally destructively, they begin to starve themselves. Given that getting lean, and lowering your body fat composition, is determined overwhelmingly by choosing the right diet, there’s no shying away from its importance.

By reducing your calorie intake, and subjecting your body to a calorie deficit, you reduce your body’s leptin levels, as well as its metabolic rate, which promotes fat storage. It is important, therefore, to keep calorie intake at a consistent level, but to improve the quality of your calories, favouring proteins.

Similarly, if you subject your body to a high calorie diet, the leptin receptors in your hypothalamus can become desensitised. As the receptors become more leptin resistant, they tend to err on the side of caution and deliver the message to your brain that your body should store more fat.

It’s important to strike a balance. By eating a balanced diet, leptin levels remain high, your metabolism remains high, body fat storage is reduced, and you become leaner. In essence, a balanced diet ensures that you get the most from your exercise regime, as you are building on solid metabolic foundation stones.

How to ensure that your body produces the optimum level of leptin

Ensuring that your body produces the right amount of leptin is not an exact science. As levels are not easily monitored, unless you are receiving assistance from a medical professional, even eating a balanced diet can sometimes not quite be enough. There are, however, a number of habits that you can develop to ensure that your body remains leptin rich. Here are three of the most effective.

 1.    Rest. As with any diet or training regime, the most important aspect, and often most overlooked, is ensuring that you get enough sleep. Studies have shown that leptin levels typically increase during sleep, and those who sleep sufficiently, and are rested, can produce up to 15% times more leptin that those who are sleep deprived.

2.    High-intensity interval training (HIIT). Studies show that interval training, such as Fartlek training, helps to maintain high leptin levels in the human body, through the increased secretion of human growth hormone.

3.    Cheat meals or cheat days. While your diet should be balanced and high in protein, if you are trying to reduce your body fat composition, sometimes your metabolism can slow because your body becomes too used to working at a certain level. Hunger and fatigue may be the symptoms of low leptin levels and a slowing metabolism. It’s important to recognise them. In this scenario, the best thing to do is to eat a high calorie and high carbohydrate meal as a means of kick-starting your metabolism and increasing your body’s leptin levels. This can be one cheat meal or it may be a cheat day. The important thing is that it doesn’t lead you to sliding back into old, bad habits. See it as a reward for all your hard work.

Lean and mean

The road to achieving a lean physique can be a long one. Reducing your body fat composition is far more complex than simply exercising and decreasing your calorie intake. The good news, however, is that with a little bit of knowledge, and some hard work, lowering body fat percentage and getting lean are goals that anyone is capable of achieving. And now that you understand the importance of leptin and the inner-workings of your body a little more, the road to success just got that little bit easier to negotiate.


Gareth Evans

Gareth Evans
A former professional rugby player in his youth, Gareth is now a bit of an all-round amateur when it comes to sport. He continues to play rugby for his local club, has studied Brazilian Jiu Jitsu in Argentina, played Basketball in Peru, trekked in the Andes and the Himalayas, is a reluctant adventure racer, and is now studying KFM (Keysi Fighting Method). He has a passion for a whole host of sports, as well as travel, but feels truly at home on the rugby pitch or in the mountains.