Hunger Hormones - Part 2
Ghrelin & Leptin
Now that we’ve looked at insulin, which is the loudest hunger hormone, let’s look at the quieter hunger hormones. They play a role in your hunger every single day, but they’re rarely talked about.
Ghrelin
Let’s start with ghrelin, whose main job is to keep you from starving. …but you might feel that your ghrelin is doing too good of a job (a.k.a. asking for food ALL.THE.TIME)
Ghrelin is mostly a hormone that triggers hunger and is released when your stomach is empty. The longer it has been since you’ve eaten, the more ghrelin will be released. But it also helps to manage your glucose levels throughout the body as well as your energy balance.
…most hormones wear many hats in the body, which is why many body systems struggle when one hormone is out of balance.
One of the hats ghrelin wears is to trigger the release of growth hormone from the pituitary, which helps to break down fat and promote muscle building. It also has an anti-inflammatory effect on the cardiovascular system, but little is known about this function right now.
New research is also pointing to the possibility that ghrelin helps with memory creation and stress, which may even help develop new treatments for Parkinson’s, anxiety, and depression.
…all this from a hormone that makes you hungry :). And since we’re looking at its hungry properties, let’s dive into that.
Ghrelin is produced mainly by the stomach, with small amounts released in the small intestine, pancreas, and brain.
Ghrelin is released when your stomach is empty and quiets down once your stomach stretches when filled with food. It takes about 10 – 15 mins for this signal to reach your brain, so you might have a full stomach but still feel ravenous.
And this is often due to one little habit – fast eating.
Think about it, A LOT of food can be eaten in that 10 – 15 min window, and if you can keep gobbling up food at a fast rate, it becomes so easy to feel absolutely stuffed instead of wonderfully satisfied after eating.
So, the key is – eat slower. And, eat bulky food that takes up a lot of space, like fibrous veggies :). They also take time to chew, so that will automatically slow you down. Win win.
What you eat is also as important for ghrelin release as how you eat. Carbs and protein will restrict the amount of ghrelin released more than fat, which means that carbs and protein may be more satiating. But we also know that healthy fats help to slow down the digestion of food, which also helps you stay full longer…so all three macros are important :)
Low calorie diets and ghrelin
If you’ve ever been on a low-calorie diet you might remember feeling wildly hungry after you’ve stopped following the diet. That feeling wasn’t psychosomatic, it was due to ghrelin.
Ghrelin’s job is to keep you from starving and to your body, that low-calorie diet is creating a situation that looks like starvation. So, your body ramps up ghrelin levels to try to encourage you to start eating. A 1200 calorie diet is about half of what an average adult needs to eat each day, so it makes sense why your body is freaking out.
Ghrelin doesn’t calm down after one meal or one day after you start eating enough…it continues for a while. This is one of the reasons why weight loss from low calorie diets is almost impossible to maintain. Your body is trying to “fix” the starvation!
The body feels the size you were at before the diet was your healthy size, and now that food is available again it wants you to EAT!
Yes, this can be frustrating if you have a different idea of what body size you’d like to be, so let’s look at why your body is doing this so we can have more understanding and less frustration.
Ghrelin and Your Body’s “Set Point”
Food abundance is a relatively new concept for the body, along with fibre-free access to glucose (a.k.a. refined flour and sugar). Our bodies haven’t had a chance to adjust to this new lifestyle of ours.
Instead, our bodies are wired to cope with starvation.
And that’s ghrelin’s job! To keep you alive when food is scarce by prodding you to eat whenever there’s food available. Think about a time of starvation in the past, you might have lost a lot of energy reserves and muscle mass, and once food is around again your body is DESPERATE to create those reserves again.
Your body will also ramp up ghrelin levels if you’re exercising a lot as well. Your food intake might be fine, but if you’re burning a ton of energy reserves through exercise, it’s going to make you hungry as well.
Today, we spend much more time creating starvation to drop some of what we’ve deemed “unnecessary” energy reserves, even if your body disagrees. Ramping up your ghrelin levels to make you hungry isn’t undermining all of the work you did on the diet, it’s your body trying to get back into balance.
But…all is not lost. We can make our hunger hormones happy AND create the body we’d like (within reason, your body doesn’t want you to be under a certain body fat %...even if the magazines tell you it’s possible)
And remember, as we learned in that milkshake study, ghrelin will start to lower when you BELIEVE you’ve eaten enough.
…there’s a wildly interesting phychological aspect to ghrelin.
But, before we get into how to find balance with ghrelin, we need to look at another hunger hormone, leptin
Leptin
Leptin is made in your fat cells and helps to manage your energy storage. In a nutshell, if you have enough energy stored in your fat cells, then your leptin levels will be high. This reduces your hunger because your storage (fat cells) is nice and full. If your energy storage is low, then your low levels of leptin trigger hunger.
In a nutshell: ↑fat cells = ↑leptin = ↓ hunger
If ghrelin and leptin were two people on stage talking, you wouldn’t hear leptin because ghrelin is so darn loud. There are a bunch of new leptin supplements popping up* right now and at the moment it’s best to just ignore them. Adding more leptin to your system *may* cause more leptin resistance (since we still don’t quite understand what’s going on) and it doesn’t really matter because ghrelin will drown out the leptin anyways.
* These supplements are mostly in the US; they may never make it to Canada because they’ll need research to confirm they’re effective)
When leptin is working well in the body, it creates an optimal metabolism, balances mood, and even helps with mental sharpness. Out of balance it can lead to weight gain, mood swings, and brain fog – these are similar symptoms to low thyroid, and leptin and thyroid are connected.
There’s another problem – leptin resistance. It’s another reason why you can ignore the leptin supplements. Our cells can become resistant to the signals of leptin, so our leptin levels can be high (aka, no need for storing energy), but our body keeps sending glucose for storage. Our body thinks we’re starving even though we have plenty of energy in our fat cells, triggering lots and lots of hunger
This is something we can help :) …more on that in the next section, just wanted to give you a heads up so you don’t get too frustrated in this section :)
This is also similar to insulin resistance and high insulin levels can increase leptin resistance. Happily, similar habits can help both.
And, interestingly, men tend to have more insulin resistance, and women tend to be more leptin resistant. When was the last time you heard about leptin resistance? It’s so rare! Just another example that the mainstream advice tends to ignore women.
It looks like this difference has to do with fertility. Women are much more sensitive to leptin because their ability to carry a baby for 9 months depends on their energy stores. So, yes, this means that women are much more sensitive to weight gain and resistant to weight loss vs. men.
And, so, we just need to look at it differently :)
Lastly, it looks like our sensitivity to these hunger hormones may determine our ability to maintain our weight. So, if you’re frustrated that you feel hungry all the time even though you have plenty of energy stored…then working on your hunger hormone sensitivity might be helpful :)
So, let’s look at that – how to increase your sensitivity to insulin, ghrelin, and leptin :).
Got any questions or comments? Comment below, jump to our private Facebook Group, or the Ask Lisa page :).