Satiety: Another Kind of Gut Feeling
According the World Health Organization, there are currently over one billion overweight people in the world today. The ever-increasing prevalence of obesity in young people promises that this pandemic is likely to worsen in the coming years, putting an intolerable strain on healthcare systems. I have frequently commented on the problems of using a reductionist approach to weight management. You probably know from personal experience that any diet works for a while and then, unless something drastic happens, the weight usually returns. Similarly some of the drugs available for treating obesity may indeed work, but usually only in the short term and their usefulness is limited by side effects.
I want to say more about why the problems of weight can be difficult to manage and why the solution is not another fad diet aimed at modulating one hormone, such as leptin, or one neurotransmitter like serotonin or dopamine. I have mentioned before that there are multiple systems involving at least 260 tightly interconnected hormones and chemical transmitters coordinating the control of body weight. There are so many because weight is critical to survival and, with the possible exception of the brain, the more critical a system, the larger the number of fail safes and backups: the greater the degree of redundancy. Imagine a tent being secured by 260 ropes. But not just any ropes, these are intelligent cooperative ropes. Cut one, and the tent will stay in place because there are still hundreds left in place. Give it a little time, and the remaining 259 ropes will take up the slack, and the tent remains unmoved. Professor Steve Bloom from the Hammersmith Hospital and Imperial College Faculty of Medicine in London, has been a world leader in research into intestinal hormones and weight management for over thirty years, and he has just published a brief overview that focuses on just a few of the hormones known to be involved in the maintenance of body weight, and highlights the reason why some of them are attracting the interest of pharmaceutical companies. As well as holistically-oriented physicians.
It is now known that the regulation of appetite and food intake involves a complex series of interactions between higher cognitive centers in the brain, more primitive brain regions that we share with birds and reptiles, and the rest of the body. Amongst the key players in this whole vast orchestra are the endocrine systems of the gut, that play an important role in inducing and maintaining feelings of satiety.
The list of gut hormones involved in the maintenance of weight is a long one, that can be confusing to people who are not expert in the field. Here are just a few of them:
- Cholecystokinin
- Glucagon-like peptide 1
- Peptide YY
- Oxyntomodulin
- Ghrelin
- Pancreatic polypeptide
This is by no means the whole list, but you get the idea. At least one model for obesity suggests a breakdown or deficiency of some of the gut hormones that normally signal satiety. In effect, people do not know when they are full. In addition, disturbances of some of these hormones may lead to fat being deposited in some of the danger areas of the body, particularly inside the abdomen.
If I were to give you a breakdown of all the recognized weight control systems in the brain, I think that both of us would probably fall asleep
Yes, these understandings will enable drug manufacturers to produce new drugs to help with obesity. But that is only part of the story. We have found time and again, that the most effective way to normalize weight and eating habits is to deal with it from five different directions:
- Physical
- Psychological
- Social
- Subtle
- Spiritual
In previous articles I have already given some broad brush strokes about what constitutes healthy eating. Strategies that work WITH rather than against systems that have been evolving for millions of years. In future articles I shall also share some of the weight management techniques that I detail in my book Healing, Meaning and Purpose.
Technorati tags: satiety, weight loss, weight control, diet, holistic diet, healthy eating
Dr. Richard G. Petty, MD is a world-renowned authority on the brain, and his revolutionary work on human energy systems has been acclaimed around the globe.
He is also an accredited specialist in internal and metabolic medicine, endocrinology, psychiatry, acupuncture and homeopathy. He has been an innovator and leader of the human potential movement for over thirty years and is also an active researcher, teacher, writer, professional speaker and broadcaster. He is the author of five books, including the groundbreaking and best selling CD series Healing, Meaning and Purpose. He has taught in over 45 countries and 48 states in the last ten years, but spends as much time as possible on his horse farm in Georgia.
As someone who has spent most of my carreer studying affect, I have long been fascinated by “gut feelings.” Isn’t amazing how many of our “neurotransmitters” were originally found in the gut?
I really like your 260 tent rope analogy, and feel that will be a great help to organizing knowledge on the fat storage system.
Before Candace Pert was somewhat chased from NIMH, I seem to recall her going in some interesting directions with some of these molecules that show us there may not be such a fine line between a hormone and a neurotransmitter.
I think that you are quite right. The field has moved forward very rapidly and it is now clear that many neurotransmitters do not just pass messages but also modulate the growth of dendrites and new neurons; and many neurons release peptide hormones. And there’s a huge amount of new data on the effects of hormones on the brain. I could fill the entire blog with some of that material. It is so important and so little known. There are some good evolutionary reasons for the common occurence of many of the same hormones and neuotransmitters in gut, heart and brain.
In the next day or so you will see another article on the distinction between instinct and intuition where I talk about “gut feelings”, and if you are interested in them you may also like to have a look at my review of a great book: http://www.amazon.com/gp/product/0195151453/ref=cm_aya_asin.title/104-0728113-7786351?%5Fencoding=UTF8&v=glance&n=283155
I’ve already got that book in my Amazon cart…
I feel I have a strong sense of the difference between instinct and intuition, so I look forward to your thoughts on this.
I firmly believe Freud overestimated the role instinct in human behavior. My sense is that although valuable evolutionarily, instincts present themselves often as relatively subtle whispers, and it is only after they are “co-assembled” with affect that they assume actual importance.
I always told students to remember a time when had to urinate fairly urgently and then something caught their interest and they actually forgot about it for a while, or to imagine being a teenager parked on a back road in a car with your girlfriend… Can’t get closer to Freudian instinct than that, but what happens if a police officer bangs on the window with his flashlight…
I think it is the fact that insticts assume conscioussness very subtly that lead folks to confuse them with intuition, which also tends to appear “quietly” in our noisy western minds.
I think that you’ll find a lot to agree with in my article, and when you see my discussion in Healing Meaning and Purpose on the ego-fears, which are genuine instincts.
Though Freud created some new ideas, he was also a child of his time, and it is interesting to frame his concepts in the prevailing intellectual currents of nineteenth century Vienna. The whole Weltanschauung of the German- and French-speaking worlds were firmly based on biological determinism.
One of the astonishing things about so many species, and not just humans, is our ability to over-ride instincts. One of the reasons why I remain firmly committed to the notion of free will. As I look out of the window I can see a flock of migrating geese swimming around on the pond. They will fly away when the amount of ambient light and the temperature changes.
But I’m pretty sure that you are not a goose!
It’s not instinctive for a horse to carry me around, but he can learn to really enjoy doing it.
Having yourself on a horse’s is such an excellent example of overriding instinct. So much of the horse’s instincts evolved during it’s existance alongside the big cats. The cats attacked by jumping on the horses back, so we sure are asking hugely for them to over-ride their instincts. In the most basic of horse training, we teach them to “yield to pressure.” Horses ‘instinctively’ push back against any pressure. It is thought this had the function of not having them be eviscerated if a cat stuck his claws into a horse’s side. Horses are such a wonderful example of free-will overriding instinct, and an intense level of trust they can demonstrate with their incredible ability to bond with us. I can go on about equine psychology all day…
You are, of course, absolutely right on each count.
Equine psychology is fascinating. People who do not work with them usually assume that we are just anthropomorphizing, but I’m sure that we are not. Once, as I went to bring in my late horse, his pasture mate took my horse’s bridle, threw it on the ground and stamped on it. He then glared at me. Because he wanted to come in first. Think about the number of steps involved in those actions. We estimate that he is cognitively at roughly the level of a seven year old human, and like all of his kind, he has clear ideas about fairness, propriety and even altruism. He’s also a big show off!
Do you know the book Equine Behavior, by Mills and Nankervis? Though some of it is very basic, there are some interesting insights. It’s a nice complement to the Monty Roberts and Rashid materials, IMHO.
I thought I had such a large bibliography on the equine behavior/psychology books, but I was not aware of Mills & Nankervis work. Another addition to one of my Amazon lists…
That is such a wonderful horse behavior anecdote. It really would put that horse at least at the level of a 7 year old human.