Monday, September 29, 2008

The Leptin Connection

New research on the science of weight focuses on leptin, a hormone associated with regulating food intake. If your leptin levels are sufficient, when you eat, they signal satiety to the brain. "You've had enough" or "You're full," the leptin communicates. So, what effect does dieting have on leptin levels and what happens when leptin levels are insufficient?

A new study by Columbia University Medical Center, published in July's Journal of Clinical Investigation, suggests that obese participants who dieted down to lower weights experienced significant reductions in leptin. . . related to increased food intake. Implications for weight loss? When you diet, your body works overtime to help you re-gain the weight, explaining why over 95% of all diets fall.

The Columbia Medical Center Record quotes Dr. Rudolph Leibel, an investigator on the project:
Weight gain is unfortunately very common following otherwise successful weight reduction. . . . Brain images confirm that the body is subject to powerful biological forces that regulate food intake--forces that are beyond an individual's conscious control. Obese people who may have struggled to shed 20 pounds will have lower blood levels of leptin that will cause persistent hunger. Combined with reduced energy expenditure--also caused by lower leptin--that's the perfect storm for re-gaining the weight.

14 comments:

Anonymous said...

More evidence that "listening to your body" doesn't work all the time for reaching and maintaining an ideal weight. Though I'd suspect eventually leptin levels would renormalize at the healthy weight after some time.

Brian said...

So the only catch with "otherwise successful weight reduction" is gaining back all the weight. I dunno. That seems like a significant catch to me. That's like, "its a shame that crashing into an iceberg ruined an otherwise successful maiden voyage for the Titanic".

purplegirl said...

Dieting makes you hungry? Really? Thank you, scientists!


It's been a while since I've read up on this stuff, but I think the picture is a little more complicated. I believe the hormone ghrelin is also a significant factor. There's also another hormone, the name of which I can't remember, that makes your body more likely to store energy after a significant weight loss.

Also, if I'm remembering right, the influence of the hormones can be minimized. I think it's most likely to trigger weight re-gain when a person diets down to a certain weight and then immediately goes back to a "regular" diet. I believe gradual changes back to a non-weight loss diet gives the body time to adjust and not pump out those hormones in such unbalanced proportions.

Ellen Mint said...

Leptin is actually a very complicate hormone. It doesn't just regulate making you hungry it also regulate the formation of adipose tissue and other hormone secretions.

What no one ever tells you is that adipose tissue does more than just acumulate and provide food storage. It's incredibly complex tissue.

Of course the only way I'd learn about this is doing some dairy research on cows.

wriggles said...

The reasoning behind this study is that fat people eat a lot because they are more hungry.

This is a departure from fat people eat too much because they chose to.
I hope they don't get into trouble for being revolutionaries.

PTC said...

I don't like those results.

Mike Hunt said...

I am so glad the we now have leptin now making people fat. Thank you Scientists for bringing us leptin here in the US. As a feeder and a fat admirer I only wish leptin was around 20 years ago. Will we start exporting the stuff so that other countries can get all nice and fluffy like the US of A?

Anonymous said...

The thing that is missing is the leptin levels in post fat people are the same as those in normal people. Fat people have less leptin receptors because they eat so fucking much. When their leptin levels return to normal they number of leptin receptors increase. You conveniently left that fact out.

If you lose weight and keep it off your leptin levels will return to normal as will the leptin receptors.

Lisa Sargese said...

I think using Leptin and other physical solutions helps folks like me to have the odds stacked in my favor. It's hard enough to battle an eating binge disorder psychologically. It's good to have the physical support as well.

Shira said...

The problem I have with this is it still works on the assumption that fat people eat more than thin people, which on the whole is absolutely not true. I could never eat the amount my husband does, and he has a BMI of 21. He's always worried about how little I eat, despite the fact that I am not hungry, and my BMI (for what it's worth, which isn't much) is 43 and rising. I know plenty of people like both of us. I'm tired of all the "research" that initially looks like it's somewhat fat-friendly but essentially boils down to "Ohhh, so THIS is why fatties are fat! It's not that they *won't* stop eating, it's that they *can't*!"

Anonymous said...

My question is, what does "sufficient" mean? Who decided, and based on what exactly, at which point someone's Leptin levels are deemed "normal"? What makes them "normal"? Are they just "sufficient" if they have kept you thin so far?

I'm beginning to suspect that we're dealing with a bad case of circular reasoning here, like "Fat equals unhealthy, therefore fat people's characteristics must be abnormal, and now look - fat people have abnormal characteristics! Which proves that they are unhealthy."

Have they never considered that adequate Leptin levels could possibly vary from person to person?? I'm certainly not an expert, but this is not the first time that scientists seem to have conjured up their standards out of thin air.

Anonymous said...

I'm 22 weeks pregnant with twins. It'll be my 2nd and 3rd baby in 2 years. I went from a vegetarian calorie counter, like the crazy sort where you measure all your portions into ziploc bags and such!

My body always has seemed most comfy at 170lbs, and too keep at 150lbs I worked two jobs and ate with everything measured out plus yoga and running. My suggested body weight is 120... I would have too have an eating disorder for sure too be that thin.

Anyway, my point being is I ran into your blog after looking for how too count, more, so I don't get morbidly obese during this pregnancy. My husband was told by a man last pregnancy that I was going to 'get fat' and too watch how I eat. I don't get it. So I go to get weighed and I gained 8 lbs in two weeks.
As we all know, this can be traumatizing. Standing on the scale waiting for them too tell us that horrid number. My doctor told me I needed too watch my weight and that I don't have to excessively eat. The thing is, I have too force myself too eat as it is!
So this skinny stigma carries over into pregnancies too. All the magazines of these mom's pregnant with twins and they look awesome,skinny, and flat after they give birth. I wish that was how it really worked.
You've helped me focus on the being happy part of my pregnancy and just enjoying my time with my growing babies. It's nice too see other ladies with the same ideas of themselves. I was really starting too think I was sick.
Here's too staying healthy and happy!

Cathy Adamkiewicz said...

Thank you for this excellent info!
Something many of us have experienced first hand.
I'm a first time visitor to your blog -- so intrigued by the title I had to visit. I wholeheartedly agree. I am convinced that many of us(myself included) are battling nameless eating and body image disorders. I'd love for you to visit me at my blog (one that examines the intersection of faith and fitness) at templeofthespirit.blogspot.com.
I'm looking forward to visiting here often!

Fat Bastardo said...

This is more of the old style fat acceptance malarkey. Men and women have similar leptin levels as they have similar obesity rates. If you take testosterone out of the equation the obesity rate would probably be higher among men but right now its almost neck and neck. Also the criteria for determining obesity is biased against women. Women are supposed to have more fat.

I am the owner of BiggerFatterBlog.blogspt.com We are taking up the slack in the fat acceptance/obesity promotion movement due to the venerable Big Fat Blog shutting down. As the new voice in fat acceptance we are busting all the pseudo scientific myths and replacing them with common sense

One of the reasons FA has not hit the mainstream fat community is because of silly notions like leptin, PCOS, Syndrome X being the cause of obesity when it is really the other way around. When I was an active NAAFA boarder and still drinking their Kool Aid I knew deep down I was spouting crap because 30 years ago people were stressed out, they had fast food, and frozen meals obesity was rare. I am not going to blame some hormone because I am fat and gluttonous. I am fat and I am proud of that. I am a greedy glutton and I am proud of that too.

Leptin, diabetes, nor stress makes us fat. Eating delicious high calorie foods makes us fat. For me it is worth it and I am not going to apologize of look for excuses to explain my size and health issues. I am fat because I eat a lot of calories and I eat a lot of calories because like most of you I love food above all else.