This post is also available in Dutch.
During the holidays, we think of food (and endless Christmas jingles). People can eat 4,500 calories on Christmas day alone. So how do we prepare for such a gluttonous undertaking?
Your mouth begins to water
Even when we only look, smell or simply think about food, our mouths begin to water. This is a specific response that occurs when we see, smell or think about food. For instance, when something has a sour taste, we tend to produce more saliva. As result, eventually just the packaging of sour candy can trigger the production of more saliva. This association that triggers salivation can be seen as a form of Pavlovian conditioning, an effect that was accordingly discovered through the study of salivation (in dogs).
Our brain ‘sets the table’
When it comes to seeing even our first serving on Christmas day, our brains will immediately draw upon our previous memories of that first meal. During this moment, our brain will determine whether we are hungry or thirsty. Given this information, our body will prepare itself. While saliva is being produced, our body also begins to produce hormones. Insulin is one of these hormones and ensures that glucose (blood sugar) is absorbed, which is present in blood after we eat. The early production of insulin may sound premature (when only seeing or thinking of food), but research tells us that the early production of insulin allows us to process blood sugars more easily. If this process doesn’t run smoothly and the role of insulin is disrupted, this results in diabetes (‘sugar disease’) and can lead to serious health problems.
So when we begin to think about food, our brain puts our body to work. Consequently, the preparation our body makes also has an effect on our brain. The production of insulin ensures that our blood sugar levels decrease. When blood sugar drops, this decrease signals our brain to eat so that we can avoid an energy shortage from occurring. Therefore when we think about food, we usually eat shortly after!
So why not look forward to eating Christmas dinner every day? When our thoughts about turkey increase then the likelihood of us overeating also increases. On the other hand, our thoughts can also help us avoid overeating. In an American study, participants were given the exact same milkshakes on two different days. On one day the milkshake was labeled delicious and read, “Enjoy! You’ve earned it!”, and on the other day the shake was labeled ‘Sensi-Shake’ and read, “Enjoy without guilt!”. So what happened? When participants drank the Sensi-Shake the stomach produced less hormones that otherwise would signal the brain to stop eating.
So when we think that our food will be deliciously filling, it tends to fill us sooner. So to avoid overeating this Christmas, it may perhaps be in your best interest to think about how heavenly eating all that food is going to be.
This blog was written by Joost Wegman. Joost is a post-doctoral researcher at the Donders Institute. He researches how ideas influence our eating experience and how saturation works in the brain. Fortunately, he can separate work and social life, this way he can fully enjoy meals.
Translated by Marpessa.