|How Leptin and Insulin Signal Satiety|
Source for Graphic: Wiki.Brown.edu
I have been stamping my feet and complaining for the last six weeks because of having to wear a CPAP mask (Continuous Positive Airway Pressure, a therapy designed for people who stop breathing during sleep, and, therefore, wake up several times during the night. Sleep-deprived people can experience serious medical problems, such as heart disease, high blood pressure, and obesity, among other ailments).
I grumble every single night. My better half must be sick of my constant kvetching...
But for the first time since I can remember, I’m getting good sleep and waking up energetic and exercising regularly.
About four weeks into the CPAP therapy, I also noticed something else: my appetite has started to regulate itself, which has been a total surprise to me because I have always had an out-sized appetite. I never really knew the difference between hunger and satiety – I would go from being starved to being overly full (and it took a lot to get there). Yes, I would diet, but it was a struggle because my body was fighting the diet every inch of the way (excuse the pun) and the constant hunger just got to me eventually.
But now I’m beginning to recognize the satiety signals that my body gives to me.
About six weeks ago, I started back at Weight Watchers, not too optimistically, because I have done this chapter and verse numerous times before (the last time discussed on this blog), only to put most of the weight back on. But this time I started with the determination of losing the weight so that I can lose the CPAP, still my goal. That’s a powerful reason to put up with constant hunger pangs.
So when my appetite started normalizing, I just couldn’t believe it; I’m not sure I still believe it, that I will discover that this is just an aberration and that motivation is the real impetus.
I had read somewhere – God knows where – that sleep deprivation and obesity were related. Was I sleep deprived because I was obese, or was I obese because I was sleep deprived? Who knows?
I did a little research: I already knew about insulin resistance, but then I stumbled upon the word “Leptin” (stay with me, I'm not trying to sell supplements or anything), which is simply the hormone that regulates hunger (among other functions, such as building bone).
There is an actual serious medical condition called Leptin Deficiency (NIH article); people who suffer from this deficiency are usually born at a normal weight, but quickly gain weight as babies because they can’t quit eating. Without Leptin, there is zero appetite control, so these poor souls become morbidly obese very quickly. (Please keep this in mind before judging someone who is morbidly obese.)
This definitely is not me; I was a fairly skinny kid until I was five or so and then just pleasingly plump. As a small kid, I don’t remember having a remarkable appetite, one way or another.
I started noticing a change in appetite when I was about 10 – right about the same time I started sleeping poorly. I never, in a million years, connected the two, even when I grew up and older. My grandmother (who raised me) certainly noticed my eating habits. To my embarrassment, she often told people, “Jennifer eats like three men.” And I could (not so much anymore).
The research has taken me in different directions. First, I discovered that low Leptin levels is often connected with obesity; even people with normal appetites become hungrier as the day goes on – when Leptin is normally lower – which is why even normal eaters are more likely to eat a bag of potato chips at night, but not in the morning.
Then I stumbled across some studies that suggested that sleep deprivation may lower Leptin levels even more (studies were done on CPAP users, with and without CPAP therapy), but other studies contradicted that notion, and yet others were inconclusive.
Very confusing, indeed.
Then I read an article on WebMD that makes perfect sense: that obese people often create more than enough Leptin, but the hormone never reaches the brain and appetite center; hence the term “Leptin Resistance.” In this scenario, Leptin therapy would not work, much in the same way that insulin therapy would not work with insulin resistant patients.
Leptin injections do work in people who are truly deficient in Leptin, but injecting a resistant patient with Leptin would be pointless and, perhaps, even dangerous.
(By the way, all those Leptin pills sold on late night TV and Amazon are all bogus – the 21st century version of snake oil. Stay away. The only thing that will get thinner is your wallet).
So, how to battle Insulin and Leptin resistance? All the research says: eat a diet low in processed sugars, eat healthy food (we all know what those foods are, blah, blah, blah, and they aren’t called “Twinkies”), exercise regularly, and get plenty of sleep.
Off and on, I had been trying to eat well and exercise, but the sleep component was always missing – until six weeks ago, I doubt if I had decent night’s sleep in years.
So now that I’m sleeping fairly well (some nights, I rip off the CPAP mask without knowing it), I can only hope that this is real and not just extreme motivation at work.
Time will tell.
Meanwhile, this is an illuminating WebMD article on “Leptin Resistance.”
I’m sharing this because there may be others out there who might benefit from knowing that there could be a connection between lack of sleep and appetite.