Hormones and Appetite… A Much Needed Discussion (November 2016)
How often have you wondered what role your hormones have relative to the food choices that you make, the quantities that you consume or even how your body’s make up has become what it is? These topics have been regular conversation pieces with clients at my office.
Since the focus of my practice is Intuitive Eating as well as Health at Every Size, the goal is to change my clients’ relationships with food, not to speak about weight loss. These approaches help clients explore what foods provide energy for them, make them feel empowered in their bodies and are also pleasurable to eat. Many people believe that all foods we eat must have some nutritional benefit, but it is also important to have some fun or “ineffective” choices in our daily diets or we will feel deprived. My goal in writing this article is to provide you with insight into recognizing that some of your genetically controlled hormones may impact your food choices as well as when you eat.
Clients understand that embracing intuitive eating is a long journey to work on. For many, embarking on this process begins with working on the “radical acceptance” of aspects of their lives which they are not able to change, e.g. what their genetics are. No one can be certain what his/her body makeup is naturally meant to be as dictated by genetics. I like to begin educating clients, and my readers as well, by touching on the functions of several hormones, bodily aspects that are genetically controlled.
Leptin, which is also known as the satiety hormone, is secreted by fat cells to regulate energy metabolism and to signal the brainto suppress the appetite, i.e., decrease our food intake when we are satiated (full). Research has shown that when someone is obese or has been chronically dieting, even though her/his leptin levels are high, leptin resistance is the reason the body is not registering the satiety signal. Since that satiety signal does not register and energy metabolism is not adjusted, the obese person is likely to continue eating while the body is storing that food-energy (calories). This leptin resistance is the reason an obese individual does not feel satiated.
The opposite of feeling satiated is being hungry. Ghrelin is the hormone in charge of hunger. Ghrelin was discovered in 1999 and works on a cycle: it rises before meals and drops after meals. This occurs organically approximately every four hours. This is the reason it is important to develop consistency with our eating schedules so we can avoid reaching extreme levels of hunger. Ghrelin levels double before meals, which explains the high levels after the fasting that naturally occurs overnight. It has been reported that if one sleeps two hours fewer than what the body needs the ghrelin levels will be high the next day, therefore, obtaining adequate rest is a key aspect of health and well-being. The ghrelin levels decrease to their lowest after meals.
Ghrelin is secreted in the gut but also signals the same cells in the brain as does leptin. Stress and depression cause levels of ghrelin to increase, which can lead to emotional eating as a means of anxiety reduction. It is important to note that this hormone does not build up in the blood stream but rather it works in the short term, i.e. within a few minutes or an hour.
Individuals with genetic disorders such as Prader-Willi syndrome seem to have high levels of ghrelin in their bodies, which can lead to extreme overeating because of the excessive hunger. Research also shows that an individual may crave high fat and high sugar foods when this hormone is elevated.
Many of us have heard of the word Dopamine, correct? This is the pleasure hormone. Dopamine is correlated to food and mood. When we are sad, which can occur when dopamine level is low, often the tendency is to select foods that provide instant gratification or comfort. For example, macaroni-and-cheese not only can provide comfort but it also can take us back to a place that is positive and memorable. The food choices that are typically selected for comfort are usually associated with cravings and the pleasures provided by food. “When a person is obese they have a blunted dopamine pathway from having the chronic exposure to highly palatable foods”, according to Heather Leidy, PhD, assistant professor of nutrition and exercise physiology at the University of Missouri in Columbia. A “blunted dopamine pathway” would lead to low dopamine levels.
When we eat, dopamine rises and when we consume high fat foods and high sugar foods dopamine levels will rise also…but what about the impact of protein? Leidy and her colleagues did a study in August 2014 comparing the satiety effects of high protein breakfasts (35 grams of protein) vs normal protein breakfasts (13 grams of protein) or skipping breakfast. Their subjects were overweight and obese late-adolescent girls. The results indicated that the high protein breakfast reduced cravings, increased satiety after breakfast, and increased post-meal dopamine levels. According to Leidy this was the first study that demonstrated dopamine increases when protein is consumed. “Protein contains amino acids, several of which are building blocks of dopamine.” It appears that increasing the protein consumption will increase the dopamine production.
There is also research done by Leidy that shows increased satiety and reduced appetite occur when people of normal weight consume a high protein breakfast.
By focusing on the three most widely known hormones (leptin, ghrelin, and dopamine), this article could be a pathway for future discussions about the variety of other appetite-regulating hormones that enhance communication between the brain and the gut.
References:
- Diz-Chaves, Yolanda. “Ghrelin, Appetite Regulation, and Food Reward: Interaction with Chronic Stress.” International Journal of Peptides. 2011; 898450
- Hoertel, Heather A., Will, Matthew.J., Leidy, Heather J. “A Randomized Crossover, Pilot Study Examining the Effects of Normal Protein vs High Protein Breakfast on Food Cravings and Reward Signals in Overweight/Obese ‘Breakfast Skipping,’ Late-adolescent Girls.” Nutrition Journal, 2014;13:80.
- Hillman, Jennifer. “Ghrelin Biology and Its Role in Weight-related Disorders.” www.discoverymedicine.com, 2011.
- Blum, Kenneth. “The Addictive Brain: All Roads Lead to Dopamine.” http://colliersmagazine.com/article/addictive-brain-all-roads-lead-dopamine. (accessed April 24, 2015).
