Leptin The Primary Fat Loss Hormone
By now you’ve probably at least heard of the hormone leptin.
Leptin is a hormone secreted by your fat cells which are primarily responsible for helping your body regulate your body weight (1) and your metabolism.
It is the single most important hormone when it comes to managing your weight, hands down.
No other hormones come close.
Not thyroid hormone, not insulin, not cortisol.
Yes, all of these other hormones are important when it comes to your weight but they all play smaller roles when compared to leptin.
Why then, if leptin is so important, do we never really talk about it?
When was the last time your doctor, for instance, mentioned your leptin level or even tested it?
Probably never (unless you frequently read my blog).
This is a shame because understanding your leptin level is incredibly important if you are interested in weight loss.
With that in mind, we are going to talk about how to interpret and understand what your leptin level means, whether or not you want high or low leptin, and how that will influence your ability to lose weight.
Let’s jump in:
Leptin Levels: What Do you want?
There is a lot of confusion regarding leptin levels and what your leptin level should be.
Let me first start by explaining how leptin works so you get an idea of what I am talking about.
Leptin levels are secreted from your fat cells and they signal to your brain to INCREASE your metabolism and to INCREASE fat burn (2).
The bigger your fat cells are (remember fat cells grow they do not multiply) the more leptin is secreted.
And this makes sense, right?
The more fat you have on your body the more leptin you want to be secreted in order to help IMPROVE your metabolism to help your body BURN that fat.
It makes perfect sense!
Ah, but there is one big problem.
This works well in theory but what most people misunderstand is that high leptin levels lead to something called leptin resistance or decreased leptin sensitivity.
This is why there is so much confusion about leptin levels in general.
Increasing your leptin levels doesn’t always result in weight loss.
In fact, increasing your leptin levels can do the exact opposite thing in many cases.
So if you are someone who is confused about what your leptin level ought to be then this information is for you!
In order to understand where your leptin level should be you need to understand something called leptin sensitivity.
Understanding Leptin Sensitivity
Leptin sensitivity refers to how sensitive your cells are to the leptin that is floating around in your bloodstream.
It’s very possible for you to have incredibly high levels of leptin hormone in your bloodstream but your body is not able to recognize those levels or even utilize them.
When this occurs, and it does in many people, you are considered to have leptin resistance.
Leptin resistance means that your cells are quite literally resistant to the leptin that they see.
And this process occurs in the same pattern as insulin resistance and progesterone resistance.
Both of these resistance syndromes stem from high levels of the target hormone.
And they occur because of feedback loops that your body uses to prevent excessively high levels of certain hormones from causing issues in your body.
They are kind of like a fail-safe system that your body uses.
And this is why you don’t necessarily want high levels of leptin.
Instead, you want a high level of leptin SENSITIVITY.
Leptin sensitivity refers to how sensitive your cells are to the leptin levels that they encounter.
High levels of leptin sensitivity are REQUIRED for your leptin to work which means they are REQUIRED for weight loss.
And high levels of leptin from lots of fat cells lead to leptin resistance and DECREASED leptin sensitivity.
Low levels of leptin INCREASE leptin sensitivity and REDUCE leptin resistance.
Understanding this concept is so important! Make sure you read and re-read it if it isn’t sinking in on the first pass.
High Leptin Levels – Good or Bad?
When do you want high leptin levels?
You’ll commonly see bodybuilders talk about leptin levels and why you want HIGH leptin levels.
They promote high leptin levels because they will obviously help your body burn fat and lose weight.
But this only works IF, and this is a big if, your body is ALREADY sensitive to leptin!
And in order for your body to be sensitive to leptin, you really need to be around whatever is considered a “normal” weight for your body.
If you are someone who is 30+ pounds overweight and you are listening to bodybuilders on youtube talk about how to increase your leptin level you are listening to the WRONG information.
Their information would be helpful but really only if you were 5-15 pounds overweight and IF your body is already somewhat sensitive to leptin.
If you are someone who has leptin resistance (again, go back to that 30+ pounds as an example) then increasing your leptin levels will only make things WORSE.
Higher leptin levels, in the setting of leptin resistance, will only yield worsening leptin resistance and therefore difficulty in weight loss.
This point is often lost on people who don’t understand the concept of leptin sensitivity and leads to a LOT of confusion.
Are the bodybuilders wrong when they say you want high leptin levels to help burn fat?
Not at all, but they are supposing that you are already leptin sensitive.
If you aren’t, then their advice really doesn’t apply to you.
Low Leptin Levels
But do you really want to have low leptin levels?
The answer here is obviously no as well.
In fact, having no leptin levels is just as bad as having EXTREME leptin resistance.
Both low leptin and extreme leptin resistance lead to the same symptoms:
- Weight gain
- The inability to lose weight (weight loss resistance)
- Extreme food cravings
- Inability to lose weight despite exercising
- And so on…
The treatment for both is obviously different but the manifestation of the symptoms is the same.
When researchers first discovered leptin they were super excited because they thought that they found the “cure” for obesity.
If you could simply give someone a leptin shot or leptin in medication form then surely you could help anyone lose weight, right?!
In theory, yes, but they quickly found out that giving people leptin actually increases weight through the process of leptin resistance (discovered above).
Now we know that prescription medications targeted at treating obesity do much better for weight loss when they target leptin SENSITIVITY and not your leptin level.
Does that mean leptin medications do not have a place in the treatment of obesity?
Not at all.
There is still a place for medications that contain leptin but only for those people who have genetic mutations which leave them with virtually no leptin levels.
In this case, some leptin is required for fat burning.
But you can’t really consider those with zero leptin in the same boat as those with low leptin or leptin resistance in terms of treatment requirements.
So, if you are someone with leptin resistance meaning you have high leptin levels and the inability to lose weight, do you really want to lower your leptin levels?
Yes, but only slightly and only for a short period of time.
For instance, if you are someone who is 50+ pounds overweight and your fasting serum leptin level is 45 then it’s a good idea to reduce that leptin level down 10-15 points in order for weight loss to occur.
This drop in leptin still maintains a relatively high leptin level (which is required for fat burning) but one which is lower than your “old” leptin level.
Lowering the leptin level here helps to IMPROVE leptin sensitivity while simultaneously keeping the leptin level somewhat high to help stimulate both metabolism and fat burn.
Treating Leptin Resistance
How do you treat leptin resistance if you have it?
As I mentioned previously, most doctors are completely clueless when it comes to this topic.
To make matters worse, pharmaceutical medications are not really targeted at leptin (yet).
This leaves you with few pharmaceutical options and of those which are available they must be used off-label.
They still can and do work, but getting them from your doctor can be difficult.
Prescription medications that help target leptin resistance include:
- GLP-1 agonists
- SGLT-2 inhibitors
- Salmon calcitonin
- And Naltrexone
I’ve written about these medications in detail in this article which I would encourage you to read if you are overweight and trying to lose weight.
Is it possible to improve leptin sensitivity through the use of over-the-counter supplements?
The answer to that question is yes and I’ve had great success with certain supplements.
Supplements are great because they do NOT require a physician’s prescription and they can be used right away.
Supplements that I find to be effective in treating leptin resistance include:
- GAGs (glycosaminoglycans)
- High doses of fish oil
- Supplements that improve thyroid function
- Supplements that improve insulin resistance
These therapies are all designed to help MANAGE or regulate leptin levels by improving leptin sensitivity.
That’s how they help with weight loss, by regulating your hormones.
If you have leptin resistance you will want to layer therapies on top of each other.
So make sure that you ALSO exercise and that you ALSO eat healthy when taking leptin supplements or when using leptin medications.
Balancing your leptin level is probably one of the most important things you can and should do if you are interested in weight loss.
I am of the opinion that EVERYONE who is overweight has SOME issues with leptin.
I think in the coming years (probably a decade) we will start to understand just how important this fat-regulating hormone is.
In the meantime, however, it will be up to you to do your own research and find your own therapies/treatments.
Until then, if you follow the standard weight loss advice of eating less and exercising more you will continue to have about a 1% success rate in losing weight and keeping it off (these aren’t my statistics but the actual numbers from people trying to lose weight).
The key to long-lasting weight loss is targeting the hormones which regulate your body weight such as leptin (the primary one) but also others such as thyroid hormone.
Now I want to hear from you:
Do you have leptin resistance?
Have you had your serum fasting leptin levels checked?
If so, what were your numbers? How high is your leptin?
How sensitive do you think your body is to leptin?
Leave your questions or comments below and share your experience/thoughts!