Leptin; a key piece in the obesity puzzle?

When scientists discovered the hormone leptin in 1994, a wave of excitement spread about it's potential to be the antidote to obesity. Commonly referred to as the obesity or fat hormone, leptin is a protein that is made in our fat cells and is actually designed to protect the body against starvation.

Leptin has a simple but key role in metabolism in that it is responsible for signalling the brain that there is enough energy available within the fat cells to engage in metabolic processes. Each individual has a genetically determined 'leptin threshold' which, providing your body's leptin levels stays above that threshold, indicates to the brain that adequate energy is available, that energy can be burnt at a normal rate, and that it is safe to engage in metabolically expensive activities such as heavy exercise..

Where leptin becomes an issue is in instances such as when people diet heavily; fat is utilised from the fat cells as energy and as a result leptin levels drop, sending your brain into 'starvation mode'. Several protective processes then ensue, including stimulation of the vagus nerve which runs between the brain and the abdomen. This nerve has a role in energy storage and once stimulated, is designed to encourage increased energy uptake to reinstate leptin levels above the optimum threshold. This then leads to over-eating and the commonly known yoyo diet effect...



So is leptin supplementation the answer to obesity?

Well, no. Unfortunately as people get fatter, their leptin threshold can increase dramatically but, just as with insulin (another hormone responsible for controlling blood sugar) in type 2 diabetes, the body can become resistant to leptin, leading the brain to think it is being starved even though that isn't the case. The issue isn't that the body is deficient in leptin, but rather that it is no longer sensitive to it. Also, in people who are leptin resistant, the usual hunger satisfaction people experience from high levels of leptin is extinguished, so that hunger persists even after eating sufficient amounts. This leads to continual overeating in an effort to attain the normal 'reward' sensation of eating.

So how can we increase leptin sensitivity and help combat obesity?

There is no magic pill for addressing obesity, but the role of leptin is certainly an important one and steps to improve leptin function are highly advised. In order to improve leptin sensitivity, steps to reduce resistance to insulin and reduce levels of blood trglycerides are key. The reason for this is that insulin resistance actually triggers leptin resistance, whilst triglycerides interfere with the leptin transporter responsible for carrying leptin from the blood to the brain.

How do I increase my insulin sensitivity and reduce blood triglycerides?

Cut sugar out of your diet. Too much sugar is the number one culprit of insulin resistance and the resultant high blood triglyceride levels and leptin dysfunction. Eating a clean diet free from added sugar products will help to restore your body's natural hormonal function, boost energy levels and help combat obesity.