Is this fat hormone wreaking havoc with your body?


There is a relatively new hormone which has been found to be one of the most powerful metabolic regulators in the body. It tells your brain if you are satiated or hungry, whether you need to eat more, and whether or not you need to make more fat in your body. It’s called leptin.

Leptin is a hormone produced in our fat cells which communicate with our brain. In a healthy body, when we make more fat, more leptin is produced. This, in turn, sends a signal to our brain telling our bodies we have enough energy and we don’t need to eat more. The body will then turn to burn fat for energy. Basically, when we eat, it is the hormone that tells your body it feels satiated and full. At least, this is how leptin functions in a perfect world.

For many people, though, they may have what’s called “leptin resistance”. Leptin resistance happens when no matter how much leptin your fat cells create, your brain doesn’t receive the message that it is satiated. The brain thinks, whoa, I’m starving! And then a whole cascade happens where your appetite goes through the roof, you burn fewer calories, and all of the food you eat gets stored around your belly.

Does this sound like it could be happening to you? Read on.


In my practice, I see a lot of women with various hormonal imbalances. Some of the main complaints I hear as part of these hormonal issues is that women are having issues with losing weight, increasing appetite, and have a lot of extra stored belly fat they can’t get rid of. These things can be due to many different types of hormonal imbalances – like thyroid, estrogen, or cortisol. But, these issues could also be due to leptin resistance. And in most cases, it is a combination of more than one of the above.

Testing for leptin resistance is quite easy with a simple blood test. The optimal level for leptin is below 12. It is also important for optimal health that leptin levels do not get too low, and so it is a delicate balance. Numbers above 12 are not considered healthy and are linked to increased risk of infertility, weight gain, accelerated aging, diabetes, and heart attack. It is also a major contributor to chronic, low-grade inflammation and joint pain (it breaks down cartilage in the joints).

Thyroid-Leptin Connection

Many times, those with leptin levels above 12 will also have a thyroid imbalance. The main thyroid imbalances seen in these cases are low T3 and high reverse T3 levels. T3 is the most metabolically active thyroid hormone, so this measure is super important to know when checking out your thyroid. T4 levels are converted in the body to the active T3 levels. But, there is also something called reverse T3, which is important to look at. When the thyroid is working efficiently, T4 converts to reverse T3 (in addition to T3) as a means of getting rid of extra T4. However, if there are mental or physiological stressors present, the body will convert more of its T4 to reverse T3, which means it is converting less towards the metabolically active T3. So, these cases are where you will see a low T3 and high reverse T3.

What does this all mean to you? If you are having issues with trying to lose some extra pounds or even get pregnant, testing your leptin and thyroid levels could give you some insight into what may be the root cause of your issue.

So, what raises leptin levels?

Well, two main things raise it: poor sleep and poor stress control. Of course, there are also other major contributing factors like poor diet.

The Gist Of It

If you are overweight and having problems dropping the weight or getting pregnant, ask your functional medicine practitioner to test your leptin level and to run a full thyroid panel (including free T3 and reverse T3). If you find your leptin levels are high, there are many ways to help bring it down.

Since many people become leptin resistant by eating the standard American diet (SAD) of sugar, processed, and refined foods, this is an important area to focus on changing at first. One of the best ways to bring leptin levels and inflammation down in the body is to focus on lots of colorful vegetables, healthy fats, lean proteins, low sugar, and minimal grains.

Also, getting 7-9 hours of good quality sleep has also been shown to reduce leptin resistance. During sleep, leptin levels will rise, telling the brain that the body is satiated and that it doesn’t need to trigger an increase in appetite and intake of calories for energy. If you skimp on your sleep, though, leptin levels will drop and consequently cause you to feel hungry all of the time. Ever had that happened after not sleeping well for a day or two? I sure have.

Lastly, reducing both physical and emotional stress can help reduce leptin resistance. Physically, this includes not doing a lot of cardio workouts in the beginning. However, weight-lifting and short-term high-intensity workouts have been shown to be beneficial as long as your body is not overly stressed while doing these workouts. The other part of reducing physical stress on the body is reducing the number of toxins you use on your body or ingest.

In short, although leptin resistance is a multi-faceted issue, it can absolutely be reversed!

If you are wondering if you might have leptin resistance, I invite you to set up a free 15-minute phone consultation with me – you can schedule via our online scheduling system or calling (415) 326-3875.

Laurie Terzo