Leptin and Leptin Resistance

Have you noticed your weight increasing year after year?  Perhaps you have tried every diet strategy but yet the weight still creeps up and your metabolism remains sluggish.  You may experience hunger and cravings and never really feel satisfied after a meal.

Leptin is a hormone produced by fat cells that helps the body regulate energy by telling the brain it’s had enough to eat.  It controls our hunger and feelings of satiety.

Leptin’s action is to inhibit appetite, to stimulate the burning up of fatty acids, to decrease glucose, and to reduce overall body fat and weight.  Leptin is supposed to tell your brain that when you have enough fat stored you don’t need to eat and can burn calories at a normal rate.

The leptin system evolved to keep humans from starving or overeating, both of which would have made you less likely to survive in the natural environment.  Today, leptin is very effective at keeping us from starving. But something is broken in the mechanism that is supposed to prevent us from overeating.

Ghrelin:  Leptin shuts down hunger and makes you feel full. Ghrelin is the other half of the appetite cycle.  Ghrelin tells your brain it is time to eat, so you feel hungry.

There should be a natural balance between leptin (the fullness hormone) and ghrelin (the hunger hormone).  They follow one another through a cycle of hunger and fullness.  You want to have a good balance between these two hormones.  Leptin resistance is when your brain is so flooded with leptin all the time that it has become desensitised to the “fullness” signal the leptin sends.  This can lead to overeating and weight gain.

Leptin has other roles in relation to your health such as thyroid function, reproductive and hormone health, immune function, adrenal function, inflammation and more. However, leptin’s main role is long-term regulation of energy, including the number of calories you eat and expend, as well as how much fat you store in your body.

However, for many overweight people, their leptin signalling may not work.  With leptin resistance your body does not respond to this hormone.  When your brain doesn’t receive the leptin signal, it mistakenly thinks that your body is starving — even though it has more than enough energy stored.  When this occurs, you can gain weight, have increased body fat, and, even though there are adequate fat stores, your brain is not getting the signal that you are hungry, so you eat more. It can become a vicious cycle.

And, you can feel more tired.  In an effort to conserve energy, your brain decreases your energy levels which also results in a slower metabolism and burning fewer calories at rest.

What causes Leptin resistance?

Leptin resistance is complex and there can be many causes.  Leptin resistance almost always goes hand-in-hand with insulin resistance, so if you have insulin resistance you might also have leptin resistance.  When insulin resistance causes spikes of insulin in the blood, the brain has trouble estimating leptin levels. So, your body can become insulin resistant and your brain leptin resistant.

Other contributing reasons can be – poor diet with too high carbohydrates and sugars, processed foods, poor sleep, inflammation, environmental chemicals, high stress or too much high intensity exercise.

What you want is to regain leptin sensitivity where your brain activates the fullness signal and you feel satisfied after a meal and stop eating.  The good news is, like insulin resistance, leptin resistance can be reversed by making some lifestyle changes and repairing the metabolism.

How to balance leptin and overcome leptin resistance:

  1. Diet plays a major role in helping to balance leptin (and insulin).  A balanced diet with good quality proteins and fats and lots of vegetables, particularly green as well as increasing fibre which all helps to balance blood sugar levels.  Avoid too many sugars and processed foods with artificial flavours and colours.  Avoid snacking and stick to 3 meals daily.
  2. Optimise sleep.  Good sleep hygiene is a must, get to bed before 10pm, limit the use of screens.  Invest in a good quality magnesium supplement to relax the nervous system.
  3. Intermittent fasting - there is some evidence that practising fasting can help insulin and leptin signalling.  Start with an overnight fast of 12 hours and then extend gradually to 16 hours, at least 3 x weekly.
  4. Limit the use of chemicals in the home and in your beauty routine.  Most chemicals are endocrine (hormone) disruptors.
  5. Spend time in nature, get plenty of fresh air, sunshine and exercise but don't overdo it.
  6. Reduce stress - stress plays a big role in hunger and satiety.  Incorporate breathing exercises or meditation, reading a book or relaxing more.

When leptin sensitivity is improved, energy improves and you have better control over cravings and appetite, a faster metabolism, and lower insulin levels.