This has been around for a long time actually and it looks like the science of ‘dessert stomach’ or as I like to term it as dessert brain is being revisited.
In a nutshell it’s where the brain makes sure there’s still room for dessert, where the craving for something sweet can override our feeling of fullness.
It’s a familiar feeling for many of us where you’re feeling stuffed after dinner and yet still somehow find room for pudding. Scientists are still searching for the causes and studies in mice have found that satiated mice still ate desserts. The opioid pathway in the brain in the hypothalamus was specifically activated when the mice ate additional sugar, but not when they ate normal or fatty food. This triggered the release of endorphin hormones like dopamine which create a feeling of “reward”. This caused the mice to “eat sugar even beyond fullness. To verify their findings in humans, the researchers provided people with a sugar solution through a tube as they had an MRI scan. They found that the hypothalamus – the same brain region was activated when they tasted the sugar. There seems to be a contradictory effect that ‘fullness’ occurs in the brain by activating satiety-promoting neurons and also the stimulation of sugar intake.
To make sense of this, I’ve unravelled fullness, appetite, hormones and sugar cravings of how I make sense of it logically.
When we eat, food enters the stomach and if the meal is made up of carbs, fats and protein or a wholesome soup then it sits there longer waiting to get digested. Fullness signals get sent to the brain which usually takes around 20 minutes. So when it comes to having a desert soon after, despite feeling full there is still room for this. So the stomach stretches to accommodate this extra portion. How much is consumed however is individualistic and we also have the influence of the hunger hormones: leptin is released when full, the opposing hunger hormone ghrelin when the stomach is empty. Note that those that haven’t eaten a balanced satiating meal may be able to consume more dessert and hence why overeating can arise to fill the gap. Leptin resistance is a state where fullness signals are not sent to the brain so the person wants to continue eating and this is dangerous as it can lead to obesity if not controlled or addressed.
Biochemically we know that the combination of sugar and fat i.e doughnuts, ice cream, cheesecake takes longer for the brain to recognise fullness, hence why these foods can easily be overconsumed in comparison to solely a sugar or fat on its own.
Parallel to this there is the fact that everyone has varying levels of dopamine and this in itself is influenced by different factors not to rule out genetics and the gut-brain axis! (Topic for another day)!! One person may need a few mouthfuls of something sugary to feel satisfied, where another none at all and someone else a couple of portions! Sugar has been shown to bind to the same opioid receptors that opioid drugs bind to. Opiods are pain relief meds like morphine and codeine if you’re wondering. Exercise also raises dopamine which is why you feel good after post workout or a walk outside and also decreases appetite. Just coming back to dopamine- Low dopamine levels are linked to low mood, poor sleep and obesity. Does this explain why some of us need some sugar/dessert/more treats to make one feel better and others binge eating lots.
Which leads me onto addictions. Dopamine being the reward neurotransmitter plays a role in this and may explain why addictions and compulsive like eating behaviours for sugar, carbs, desserts arise. The same can be applied to other addictions like alcohol, gambling and exercise. Coming back to DESSERT BRAIN does this stem from when we babies? Given breastmilk is naturally sweet and contains lactose and formula milk the same. Hence why a warm glass of milk often encourages sleepiness and calm. There is one more theory to this all where it could be evolutionary where when food was scarce helped our ancestors to survive. So sugary foods like fruits when available can be readily absorbed and metabolised as an energy reserve even today. In modern society, where famine isn’t common, food and sugar are abundant.
In conclusion we can see this a complex area and after breaking the science down, the fundamentals of healthy eating still apply to both ‘nourish’ the brain and body. Healthy balanced nutrient dense meals and low sugar puddings do control the appetite better (via leptin and ghrelin) reducing the need for snacking and consuming desserts at larger portions than necessary which in turn prevent weight gain, stabile blood sugar levels better which are all hormonally driven via insulin and glucagon. And this influences other positive health behaviours like exercise and good mood activities which impact sleep too, thus keeping domaine levels and all other hormones happy and balanced. After all everything in the body is interconnected and one system out of place has a knock on effect on others.
Thanks for reading.
