Weight Loss Surgery: Neurology And Noshing

Ever wonder why you can't stop at just one chip, M&M, or 10 cent hot wing?


We know as dietitians or well, just regular people that obesity is caused by too much (food) and not enough (activity).  This post will focus on the appetite center and hormones.  For the sake of sanity and brevity this will provide brief insight about the function of appetite and how weight loss surgery relates to these functions This post is meant to educate and not discourage or encourage someone from undergoing weight loss surgery which is a personal and medical decision.  


What really causes us to eat?  Appetite control comes from the hypothalamus, arcuate neurons located here control hormone and lipid levels, along with metabolites which affect metabolism and hunger.


"The hypothalamus controls appetite and coordinates this with energy utilization. It is, therefore, responsible for maintenance of body weight, carefully adjusting food intake to physical activity. Loss of sensitivity to hormones and metabolites in the arcuate nucleus can lead to unbalanced energy intake and use, resulting in overweight and obesity." (1)


The arcuate nucleus has two different neurons: primary neurons that stimulate appetite with neuropeptide Y and agouti-related peptide; the arcuate also has neurons called proopiomelanocortin that depress appetite.  So therefore the body has a sense of checks and balances to a point.




Some additional factors that contribute to appetite are hormones.  They are insulin, leptin, ghrelin, and a crazy gut hormone called PYY 3-36.


We know about insulin with the diabetes epidemic, this hormone from the pancreas shuttles glucose (blood sugar, i.e. energy) into the cells so they can do their thing (reproduce, work, whatever).


Grehlin and PYY both come from the stomach and digestive track.  Ghrelin stimulates neuropeptide Y and agouti-related peptide (mentioned above). PYY comes from endocrine cells located in the intestines.  It basically shuts off Grehlin and it's pro-eating peptide buddies.  The only drawback is that it takes 20 minutes to work and some of us know how much we can shovel in during that period.


Additional hormones that come from the digestive track that regulate appetite/weight functions are also: Cholecystokinin (CCK), Glucose-dependent Insulinotrophic Peptide and Glugagon-Like Peptide (GLP-1).


CCK comes from the intestine and is triggered by protein and fat.  It decreases gastric emptying (you feel full longer) and slows hunger.  It acts when food enters the duodenum of the intestine.


Glucose-dependent Insulinotrophic Peptide  also comes from the intestine besides being a long word.  It is released when glucose (carbohydrates) and free fatty acids come through.  It helps the body move energy-rich foods or Twinkees into storage, i.e. fat.  This is a good example of our caveman (and cave-woman) ancestors tracking down a mastodon and converting Calories into energy and for storage.  Since you might not know when the next woolly mammoth will come down your street.


Glugagon-Like Peptide (GLP-1) also causes a 'full' sensation by preventing calorie loss in the stool and comes from the illeum (again another function from our caveman ancestors).  It also stimulates insulin and it believed to act as a key player in diabetics who have gastric bypass done.  This is when health professionals may say that it "cures" Type II Diabetes.  On the other hand, it can also cause hypogylcemia in these individuals where their blood sugar drops out of the normal range.  

"Obesity and metabolic surgeries initially were thought to restore balance to the system primarily by minimizing intake of excess calories through restriction or malabsorption. However, while these operations can limit the quantity of food consumed, they each bring on a different change in GI hormone profiles following surgery. As more enterohormonal mechanisms are discovered and understood, operations or drug therapies may be tailored to maximize the treatment of obesity and diabetes, achieving optimal results with minimal metabolic complications." (2)




1.  "Appetite and Metabolism and Obesity."  <http://www.medbio.info/Horn/Time 5/Appetite and weight control Nov06 v2.htm>.
2.  Daniel J. Rosen, MD; and Alfons Pomp, MD, FACS, . "Gastrointestinal Hormones and their Relationship to Bariatric Surgery." . Bariatric Times, 04/2009. Web. 20 May 2012. <http://bariatrictimes.com/2009/04/17/gastrointestinal-hormones-and-their-relationship-to-bariatric-surgery/>.


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Gina Lesako RD, LD.  Gina is an Ohio based dietitian and SCAN contributing blogger.  You can follow her blog: Dietitians Eat Chocolate Too.

Yoga for Weight Loss

Yoga has been around for ages. Its popularity ebbs and flows; however, everyone practices for various reasons- stress relief, improved flexibility, balance, digestive health…the list goes on. The best part about yoga is that anyone can practice. It doesn’t matter if you’re overweight, male, female, elderly, or nonathletic. Recently, I have read more about yoga for weight loss. It’s not that yoga necessarily burns more calories than cardiovascular exercise or strength training. Indeed, yoga taps into a different area of physical activity- ‘body awareness’. If you have ever practiced yoga, be it once, only a handful of times or daily, you quickly realize how your practice focuses on becoming ‘in tune’ with your body, positive thoughts and mental clarity. Depending on how concentrated you are during your practice, it can also enhance your feelings of self-control and foster a sense of personal empowerment. Points of interest from several studies have shown the impact of yoga for weight loss:

•Over a course of 4 years, a study of about 15,000 middle aged(55 years old) adults studied weight gain fluctuation. Those adults who incorporated yoga in their physical activity experienced less weight gain, especially overweight participants.

 •Yoga incorporated into a treatment program for obese women with binge eating disorder had significant effects. The 12-week program included personal journals from each participant and ‘qualitative analysis’ of these journals indicated a positive shift in their eating habits and perspectives. According to the journals, these participants developed self-empowerment, a healthy reconnection with food and cultivated an awareness of self. All of these factors translate to better health and positive strides in an eating disorder treatment.

 •Another eating disorder treatment program that incorporated yoga for weight management found that participants who practiced for 16 weeks had significantly decreased body weight, body fat percentage, BMI, waist circumference, and visceral fat.Wow! If reading this little blurb isn’t incentive enough…

 I would be remiss to stop here without mentioning that yoga isn’t just one style. There are certain types of yoga, which range from low-impact to higher activity. Patients with injuries or less mobility might find a slower paced practice rewarding, while an athletic person looking for a cardio workout might enjoy Vinyasa or Bikram. Vinyasa is a faster paced series of poses and Bikram focuses on generating an internal heat by performing poses in an extra hot room. Depending on the activity level of the practice, more or less calories will be burned. However, all the benefits mentioned above related to mental health are reflective of all yoga practices, in general. So, if yoga doesn’t burn more calories than other strenuous exercise, how can you lose weight? The studies emphasized they did not know the specific mechanism involved with weight loss. But it seems quite simple- the combination of physical activity, body awareness and healthy eating are probably responsible for the results. When you are more aware of your hunger and body cues, you’re less likely to overeat. Developing this awareness helps to control mindless eating, which is a culprit for weight gain. Therefore among weight control, yoga promotes many healthy behaviors. If you regularly practice, you know the sense of rejuvenation. If you’re new to yoga- give it a chance to positively change your body. Any of these benefits will have you feeling better!

 Reference: http://www.todaysdietitian.com/newarchives/030612p18.shtml Drop Those Pounds With Yoga — Studies Show Yoga Stimulates Weight Loss
By Jennifer Van Pelt, MA
Today’s Dietitian
Vol. 14 No. 3

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Sara Shipley, Nutrition, Dietetics and Food Management, University of Central Oklahoma BS Student- Projected graduation May 2013

I am a nutrition and dietetics student at the University of Central Oklahoma. I am a career changer after studying and graduating with a BS in fashion merchandising and working in corporate retail buying in New York City for several years. I am now studying to become a registered dietitian because I enjoy the science of nutrition and want to share my passion for balanced eating and healthy living with others. I love helping people make educated decisions about nutrition. Eating flavorful, delicious food does not have to be compromised by choosing to eat healthy. I love to cook and eat all types of food. I am an avid runner and I enjoy writing, reading and learning about anything related to nutrition, sports, food and wellness. I practice yoga and enjoy being outdoors doing anything active,- hiking, running, walking or biking.