Hunger Hormones: Peptide YY, Cholecystokinin, Ghrelin, and Leptin
Have you ever wondered why you can be stuffed full and if you are offered another serving of meat or salad you practically get nausea thinking about trying to eat it but if offered a slice of cake, a cookie, or ice cream, you would be delighted to eat it. While everyone has different reactions to food, there are few things that are true to everyone. Arguably one of the most important factor to creating a sustainable approach to nutrition is controlling hunger. Controlling hunger is the key to creating a sustainable diet for long term results whatever style you design your diet around. We cannot outsmart our body but we can fuel it in a way that makes for controlling our appetite much easier. Let’s look at the four most important hormones that regulate appetite, cravings, and fullness.
Leptin – This hormone is secreted in the small intestines by fat cells to the adipose tissue telling the body that it has energy to use, it does not need more food. In other words, leptin is released at the end of the meal and following a meal telling the body that it does not need more food. Leptin resistance is a big problem because the hormone does not let the body know that it has energy to burn inside the body thus they need to eat more. With leptin resistance, the body tells the body its starving when it really does not need more food.
Ghrelin- This hormone rises when you’re hungry and falls when you’re satiated. In other words, ghrelin increases your appetite, leptin decreases your appetite. Ghrelin is the fancy word for hunger. Specific things can cause ghrelin to be chronically higher than usual such as poor sleep, lack of protein, and a high sugar diet. Whole foods will reduce the hormone of ghrelin quicker whereas processed foods take longer for ghrelin to drop. For example, if you eat a whole boiled potato, the body will let u know that it is not hungry anymore after a couple hundred calories of them but if you eat processed potatoes (French Fries) it is easy to eat up words of a thousand calories worth of them before you feel any satiation.
Peptide YY – This hormone is secreted by endocrine cells in the small intestine called L-cells. Similar to cholecystokinin, peptide-yy is released following the consumption of protein and fat. When the diet is lacking in foods that signal this hormone, overeating can be extremely easy. Foods like cereal, cookies, cake, pasta, chips, or french fries are not going to cause the release of peptide-yy. This is why it can be incredibly easy to eat too much when not consuming the proper foods. Proper release of peptide-yy will control your appetite and food intake.
Cholecystokinin – This is a hormone that is released by the cells in your gut signaling to the the body that it does not need more food. Specific nutrients and foods will release cholecystokinin more than others. Protein, fiber, and fat, are just a few to name. These nutrients are found most abundant in whole foods. For example, cholecystokinin will be released when eating a 16 oz steak within 8-10 ounces, signaling the body that it is satiated. The steak has no fiber but is full of protein and fat. Another example is oatmeal. Oatmeal is rich in fiber and low in protein and fat. We all know that it is nearly impossible to eat more than a 2 cups of oatmeal in a sitting. The stomach stretches and signals to the brain that it does not need more.
Factors that positively affect these hormones
1.Proper Sleep (Cool, Dark, Quiet 8+ hours of sleep)
2. Consumption of primarily nutrient dense whole foods
3. Adequate Protein Intake (I prefer 1g per pound of body weight for satiation)
4. Proper gut health (removal of gut irritating foods)
5. Low intake of refined carbohydrates and sugar
6. Adequate exercise, too much can have a negative effect on these hormones.
Summary – Optimizing hormones is incredibly beneficial in having a healthy diet. Controlling hunger is the key to sustainable health through dietary intervention. I’ve learned that when these hormones are properly functioning, simply listening to your body is an easy way to stay healthy. We often get glued to standardized meal timing and forget that our body is smarter than we often give it credit. Listen to your body, your hormones play a big role.