We eat chocolate to celebrate good times, as a sweet treat to pick us up and for the pure enjoyment of the flavour.
But there is another, more negative, emotion that pushes us towards the Dairy Milk — stress.
Chocolate can be the first thing we crave when the heat is on, and according to doctors it’s to do with our fight or flight system — our body’s ancient response to danger.
Cortisol is the body’s main stress hormone and once it kicks in it diverts energy away from the immune system, which sparks those tell-tale sugar cravings.
‘Craving chocolate is a response to a stressful situation as a need for energy,’ says Dr Nicky Keay, sports and dance endocrinologist and honorary clinical lecturer in medicine at University College London.
Chocolate can be the first thing we crave when the heat is on, and according to doctors it’s to do with our fight or flight system — our body’s ancient response to danger
‘Being stressed increases the hormone cortisol which uses our energy reserves, so we feel like we need something sweet to boost energy levels.’
But, paradoxically, simply eating sweet treats — like chocolate — can also send blood sugar soaring, followed by a crash, which can kick off a rollercoaster of stress and craving.
Food and mood: Is your sugar high making you depressed?
Most people are familiar with how certain foods can boost mood, or bring on other emotions, from a sense of calm to the jitters.
And this isn’t just in your imagination. ‘The link between blood glucose levels and mental health is well established,’ says registered nutritionist and Healthspan advisor Rob Hobson.
‘The brain relies on glucose for energy which means that low blood sugar can lead to poor brain function. This can affect our cognitive capabilities such as memory and recall, and also leave us feeling tired and irritable.
‘Elevating blood glucose levels can also cause issues, especially for people with diabetes, who can experience symptoms such as anxiety, depression, and cognitive impairment.’
More worrying is that high blood glucose levels have also been implicated in the development of depression.
‘A study of adults with type 2 diabetes, published in Diabetes Care, found that higher blood glucose levels were linked to an increased risk of depressive symptoms,’ says Hobson.
‘The results of this study suggests that poor blood glucose regulation may contribute to the development of depression.’
There’s also a wealth of research that shows how blood sugar levels can impact mood and cognitive function.
‘A study published in the Journal of Psychiatric Research looked at the relationship between blood glucose and anxiety in healthy adults and found that those with higher blood glucose levels were more anxious than those with normal levels.
‘According to other research, this relationship could be directional as both blood glucose and mental health affect each other, so people with mental health conditions like depression and anxiety are more likely to have elevated blood glucose levels, but higher blood glucose levels may also contribute to developing mental health issues.’
Hobson says that a possible explanation for this is that fluctuating blood glucose affects neurotransmitters, including serotonin and dopamine, which are crucial in regulating mood and cognition.
Another theory is that chronic high blood sugar – known as hyperglycaemia – may cause inflammation linked to depression and other mental health disorders.
‘The processes involved with inflammation may also affect serotonin production and function in the brain,’ he says.
‘When blood sugar levels dip too low, it triggers the body’s “fight-or-flight” stress response to help raise blood sugar (glucose) and fatty acids levels in your circulation as essential muscle and brain fuel,’ says medical nutritionist Dr Sarah Brewer.
‘This stress response triggers hunger so you will eat to top up your fuel levels, too, and you may experience cravings — especially for sweet, stodgy carb-laden foods to rapidly increase blood sugar levels.
‘Rising blood glucose levels then trigger production of insulin which can cause glucose levels to fall lower than usual again, setting up a vicious cycle.’
But she notes that cortisol doesn’t just rise in moments of duress. ‘Levels of cortisol are highest in the morning due to the physical “stress” of your overnight fast.’
So why is chocolate the only thing that hits the spot?
‘Interestingly, chocolate has effects on the brain to help you relax and make you feel good by increasing brain levels of several chemicals, including mood-altering PEA (phenylethylamine, related to amphetamine) which gives you a mild, confidence-instilling buzz.
‘Chocolate also contains tryptophan — a chemical converted to serotonin in the brain to lift mood and increase euphoria, plus theobromine, a stimulant which peps you up.
‘And chocolate is virtually unique in that it melts in the mouth at body temperature, producing a silky, luscious sensation that adds to its appeal and, according to psychologists, is one of the main reasons why chocolate is so addictive.’
She advises anyone craving chocolate to select an antioxidant-rich variety with at least 70 per cent cocoa solids over milk or white chocolate.
Stress isn’t the only feeling that can spark a desire for chocolate.
‘Do you find yourself craving chocolate or sweet foods when you’re angry? This phenomenon is dubbed as feeling “hangry” (hungry and angry),’ says Dr Brewer.
‘Scientists found there’s more involved than simply feeling irritated because you’re stressed by hunger, however. It’s thought that experiencing aggression when hungry is a survival mechanism that would have helped our ancestors survive when they had to hunt for food.
‘When you are hungry, the brain is starved of glucose and this impacts on your ability to exercise self-control, meaning that you’re more likely to exhibit bad-tempered behaviour or aggression.
‘In addition, when glucose levels are low, the brain releases stress hormones, adding to your bad mood. To avoid getting hangry, scientists recommend eating small portions of nutrient-dense foods at regular intervals to keep you well nourished.’
There’s another reason why we scoff chocs when the chips are down — it makes us feel better.
Rob Hobson, registered nutritionist, sports nutritionist and advisor to supplements supplier Healthspan, says, ‘Some animal studies have shown that physical or emotional distress increases the intake of food high in fat and sugar.
‘It’s thought that raised cortisol levels in combination with insulin could be responsible.
‘And once ingested, foods high in fat and sugar seem to have a feedback effect that dampens stress related responses and emotions. They really are ‘comfort’ foods.’
Conquer those cravings! Easy hacks to dampen your desire for dessert
So how do we avoid this rollercoaster of stress, sugar craving and crashing? ‘Following a healthy, Mediterranean-style, low GI (glycaemic index) diet helps to avoid these sugar swings and food cravings,’ says medical nutritionist Dr Sarah Brewer.
‘And when you fancy something sweet, opt for sweet fruit such as berries, nectarines and cherries in place of sweet confectionery and if you really must have some heavy-duty carbs, try a banana or a handful of dried fruits instead.
Walk for 15 minutes
Chocolate cravings can often be overcome by brisk exercise, which releases the brain’s own opium-like chemicals such as endorphins and enkephalins.
A 2015 study of 47 ‘overweight sugary snack consumers’ by the University of Innsbruck in Austria found that walking for just 15 minutes had lower cravings for sweet treats after exercise than people who stayed inactive.
Keep a diary
Learning to understand what you eat, and why, is the first step towards solving emotional eating, says Dr Brewer.
‘If you feel stressed, take a walk or a bath to relax, rather than reaching for the biscuit tin. Or spend 15 minutes writing about what is most important to you, whether it’s relationships, friends, music or your kids.
‘Women who were asked to write about what was important to them in a ‘feelings’ diary every day experienced fewer cravings and lost more weight over the following four months than those who instead wrote about what they thought was important to others.’
Try a supplement
Chromium has beneficial effects on glucose metabolism. It enhances the uptake of glucose into cells by increasing the number of active insulin receptors that move to the surface of cells. This makes it easier for insulin to act as the key for glucose to enter cells, leading to increased insulin sensitivity in people with type 2 diabetes.
‘Another thing people may want to consider is to try taking chromium. This mineral helps to regulate blood sugar levels and some people find that it helps them to get a better grip on sugar cravings.