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Gut feeling

Hormone may protect from obesity

Obesity is becoming a growing concern for adults throughout the province and across Canada.

According to the most recent estimates from the World Health Organization (WHO), 61.1 per cent of adult Canadians are overweight or obese with over consumption of food being the leading cause.

Appetite and energy metabolism are regulated within the central nervous system. It is through the integration of nutritional signals from peripheral organs and tissue including the gastrointestinal tract and fat tissue.

The proper amount of hormones secreted in response to eating appears to be the key to balancing food intake. Accumulated data has highlighted the importance of this brain to gut connection regarding the development of obesity.

Peptide YY (PYY) is an appetite suppressing hormone which is secreted from the gut and has been shown to inhibit appetite in both animals and humans. However, the potential protective role that PYY may play in defending humans from the rising prevalence of obesity is contradictive.

To date, there is no research available explaining how PYY responds to overeating and if this potential response varies among overweight, obese and normal weight individuals.

A study completed by Farrell Cahill, a PhD student under the supervision of Dr. Sun at Memorial University’s Faculty of Medicine, has discovered new evidence that may shed some light on how PYY reacts in certain situations.

After a seven-day positive energy challenge in 69 young male volunteers from the St. John’s area, it was found that the circulating PYY concentration increased in their bodies. The findings are a positive step in indicating that PYY is a protective mechanism working to counteract overeating.

The findings also highlight the importance and potential target for controlling appetite and the treatment of obesity in humans. These findings have been published in the prestigious American Journal of Clinical Nutrition (AJCN) (Advance online:­tent/early/2011/02/02/a­jcn.110.003624.long). The authors in the paper are in order: Farrell Cahill, Jennifer L. Shea, Edward Randell, Sudesh Vasdev, and Guang Sun.

The research team led by Dr. Sun has made many important discoveries in the fields of human genetics, endocrinology and nutrition on obesity and diabetes. The team is currently working to dissect more mechanism regarding PYY in a large Newfoundland population based study.

For more information about their team, visit