Author: Matt Whitaker, Digital Health Lead/13 December 2018
Why do we eat? Arguably if you had to answer this question in one word you may say hunger. But what causes hunger? It goes far beyond truly physiologically driven hunger, deep into our different emotions and habits and ultimately what governs these. This blog will outline what drives us as humans to crave, eat and even over eat certain foods.
We should first differentiate hunger into two broad categories, physiological and psychological. Physiological hunger is an important stimulus to ensure enough energy is consumed to sustain life, it is driven by a whole host of hormones that govern hunger and satiety- around 31 in total. Psychological hunger is more of a desire to eat, accompanied with no physical proof that it is necessary. This is controlled by our neurotransmitters which act as chemical messengers that subconsciously send signals within our body. The main two that we are going to focus on are endorphins and dopamine.
When we have empty stomachs, are losing weight, going through stressful times and have impaired sleep quality and/or quantity our body is more prone to release hormones that drive the want to eat- we can call these hunger hormones. These hormones drive such a need to eat which is near impossible to resist. So we eat- carbs are broken down into glucose, fructose and galactose; protein into amino acids and fat into fatty acids. Once these nutrients have been respectively burned as energy or stored accordingly the body recognises that it is no longer hungry and releases satiety hormones that tell us to stop eating.
This hunger centre is regulated entirely by hormones that dictate consumption of essential nutrients.
There are many reasons why we eat that can’t be explained by the above hormonal response, these tend to be psychologically driven with some examples including: emotional, boredom, habit, social and addiction.
As previously mentioned neurotransmitters have a key part to play in the regulation of psychological eating. The two that I am going to cover in this blog are endorphins which regulate our emotions, whether they be good or bad and dopamine which control habits, reward mechanisms and addiction.
One addiction pathway that is fairly well understood involves the release of dopamine which can make some behaviours become more apparent. As dopamine increases as does ones motivation to do the thing that increased it which can create a habit. As this habit is implemented this relationship becomes stronger, reinforcing the habit which may ultimately lead to addiction. To give a practical example, consider smoking which is associated with immense releases of dopamine. For smokers just the thought of a cigarette increases dopamine, seeing one increases it further and then actually having one sends levels through the roof. As dopamine increases as does positive feelings and happiness thus a subconscious relationship is formed between smoking and happiness. If continued over a period of time this association could lead to a habit and ultimately addiction. This same dopamine-reward pathway is also apparent for: recreational drugs, gambling, sex, alcohol and food.
As this blog is on emotional eating I am going to focus on food. Not all foods initiate this reward mechanism and thus host potentially addictive properties. Consider unprocessed foods that are high in just one macronutrient such as: oats, buckwheat, quinoa, double cream, oils, butter, prawns and lean meats. All of these are rarely overconsumed as they (when consumed in isolation) do not elicit a strong reward mechanism. However if we combine macronutrients in a processed manner such as in: muffins, pork pies, pizza, chicken nuggets, doughnuts etc. the reward mechanism in just thinking about these foods makes us want them and many can’t stop and just one bite! This is because they initiate a release of dopamine which follows the same mechanism outlined above.
To give a practical example: imagine you enjoy a large evening meal full of unprocessed ingredients, your satiety hormones have been released and you are no longer hungry. If you are then presented with plain baked potato- would you eat it? Probably not, however if you were presented with your favourite sweet treat you are suddenly ‘hungry’ again.
This can be expanded further when considering stress and our desire to cook and the reward mechanism. Imagine you get in from a stressful, tiring day- are you likely to prepare a meal completely from scratch or more likely to go for that convenience processed food/order a takeaway. It is more likely to be the latter due to the thought of said food initiating the feel good sensation.
Many manufacturers are aware of this which is why many processed foods are highly tuned products that are a tried and tested combination of ingredients to elicit a perfect desire to want them. They are even marketed in a way to increase the want for them. Consider the layout of most super markets, how many times do you see processed food on offer at the end of isles? This continued exposure has been shown to increase the likelihood of you picking the product up because again, they initiate dopamine and thus the want to ‘feel good’.
Even rewarding ourselves, our friends, family or partners and socialising often include food and/or drink, often consumed/drank when we are not hungry or thirsty, alcohol is a prime example here- clearly it is not drank to thirst!
Identifying why you are eating and what is truly driving the hunger is a massively useful step in preventing eating for emotional reasons. Some points to consider question yourself:
* Are you eating simply because you are bored
* Are you eating to a set routine? Do you have set meal times each day and snack at the same time?
* Are you thirsty or hungry? Dehydration is associated with feelings of hunger
* Are you being too restrictive on your dietary approach to the point you are continuously craving foods?
* Does your weekly shopping list contain the same foods week in, week out?
* Do certain emotions trigger thinking about specific foods?
* Do you always crave specific foods after consuming full meals?
* Have you ever tried to complete a food and mood diary? Seeing correlations between certain moods and consumption of foods may outline a clear pattern
* Have you tried mindfulness? A good example is snacking whilst you watch TV, this is eating without truly thinking about what you are doing/eating
Understanding emotional eating is just one part of the puzzle. Lifestyle should be considered from a holistic perspective with an emphasis put on:
* Achieving and maintaining a healthy weight
* Undertaking regular physical activity
* Eating a healthy diet
* Learning how to manage stress and sleep well
* Stopping or reducing smoking (if appropriate)
* Drinking alcohol only in moderation (if at all)
* Taking prescribed medication (when appropriate)
Overall identifying motive behind hunger may help reduce psychological eating but do consider that enjoying food is part of a sustainable healthy lifestyle.
Any questions, feedback and/or suggestions would be most welcomed, as is any request for the research supporting this blog. Please email me at Matthew.Whitaker@xperthealth.org.uk