Have you ever found yourself sitting in front of the TV in the evening and getting hungry, even though you ate a satisfying dinner? Or standing in line in a coffee shop with every intention of simply getting a nonfat latte but by the time you walk past the pastry cabinet, you decide you have to have a scone, too? Well, a new study sheds light on what may be going on with these common experiences. http://www.nature.com/oby/journal/vaop/ncurrent/abs/oby2011385a.html
You may have heard about the hunger hormone, ghrelin, which is produced in the stomach and increases right before breakfast, lunch, and dinner, triggering our desire to eat. The hormonal signals from ghrelin provoke multiple changes in our brain chemistry, increasing appetite and maybe even causing food cravings.
In a new study, Dr. Petra Schussler and her colleagues from the Max Planck Institute of Psychiatry in Munich, Germany demonstrate that simply seeing pictures of food causes levels of ghrelin to rise. Volunteers in the study were fed a good breakfast at 8:30am and then, around 10:30 am, they were shown a series of pictures. One group was shown neutral pictures of non-food items, and the other group was shown pictures of tasty savory and sweet foods. Ghrelin levels in the blood were measured every 30 minutes from the start of the study until the volunteers were fed lunch at noon. The researchers found that the group that was shown pictures of food had significantly higher levels of ghrelin, which increased immediately after they saw the pictures. Previous research has even shown that ghrelin can hit us in our wallets – when researchers injected volunteers with ghrelin, they were more likely to purchase food items than if they received an injection of water. http://www.sciencedaily.com/releases/2011/07/110712094044.htm
So, now imagine the evening TV scenario in the context of what is likely happening in your body. You’ve eaten a good dinner so your ghrelin levels are low and you don’t feel hungry. Turn on the TV to watch your favorite show and here come the pictures – commercial after commercial showing cheesy pizza, juicy burgers, and tasty desserts. Your ghrelin levels (which normally wouldn’t start to increase again until right before breakfast) start to rise in response to seeing images of foods. Suddenly, you feel hungry…hmmmm, maybe that dinner wasn’t so filling after all and I need a snack!
So, now that you know that advertisers are literally manipulating your physiology, what can you do to make sure you stick to your calorie goals? Apart from just unplugging the TV, here are a couple ideas:
- Vote with your remote: Every time a food commercial comes on, change the channel. (Unfortunately just muting the commercials won’t work because you’ll still see the images!)
- Develop your ability to detect true, physical hunger: This is a skill that needs time and practice so you can call on it when you need it. When you stay mindful and aware of what physical hunger feels like, you’ll know that you are not really hungry when your stomach is still full of dinner (regardless of what your brain is signaling!)
- “Close” the kitchen after meals: After you’ve washed up your dishes and wiped your counters, turn out the lights and tell yourself that the kitchen is “off limits” until it’s time to prepare your next meal or planned snack. I once had a patient who literally put a “Kitchen Closed” sign up – whatever works!
- Keep your motivators and core values handy: Remembering that you want to lose weight to improve a health condition, so that you have more energy, or so your knees don’t hurt when you play with your kids is a great defense against those pastry displays!
Remember, while there are plenty of environmental forces that promote overeating and inactivity, ultimately we are the ones who have the power to make choices that support our health and values. We don’t have to blame food companies, we just have to make sure we are aware of the pressures that affect us and feel empowered to make choices that support us.
About the author:
Dr. Jennifer Lovejoy is the Vice President of Clinical Development & Support at Alere Wellbeing – www.alerewellbeing.com. She holds a Ph.D. in BioPsychology from Emory University and completed postdoctoral training in Endocrinology and Metabolism at Emory University School of Medicine, where she specialized in obesity and diabetes research. Dr. Lovejoy’s clinical research program has been funded by grants from the National Institutes of Health, the American Diabetes Association, the U.S. Department of Agriculture, and NASA. She maintains adjunct faculty appointments at Bastyr University and University of Washington School of Public Health, has published over 50 scientific articles in peer-reviewed journals, over 15 chapters and review articles, and is a frequent speaker on obesity and nutrition at national and international conferences. She is the immediate Past-President of the Obesity Society.