This is what happens in your brain
How food addiction works
What wires together, fires together
Because sweet foods are linked to ancient survival mechanisms, we are highly motivated to pursue them. Our brain re-wires a little bit every time we encounter them. The brain transmitter involved in motivation and reward is dopamine.
The primitive reward centre in the brain lights up in response to sugar, releasing dopamine. If you don’t believe me, just Google ‘baby’s first ice cream’ and watch the 30 second video. We are then motivated to repeat the behaviours that led up to the dopamine release.
Your brain remembers the cues of smell, sounds and colours associated with getting ‘the hit’ and you are driven to repeat the experience in the presence of those cues.
At the same time, the brain also protects itself against these strangely high levels of dopamine by reducing the number of available receptors. Next time, you will need a bigger piece of cake or a second biscuit to get the same results. Also, I hope you can see that the brain reducing its dopamine receptors is definitely not a good thing over time. Low dopamine is implicated in depression, concentration and memory problems. Addicts focus more and more on getting their ‘hit’, but it becomes harder and harder. Then the focus becomes just getting through the day without withdrawal symptoms. There is also a tendency to reduce other interests and activities, so that life comes to focus around food and food thoughts. Sound familiar?
Dopamine is the reward and motivation transmitter whereas another chemical, serotonin signals comfort and wellbeing. Antidepressants work by making serotonin more available in the brain. When we eat sugar and carbohydrate the body releases the hormone insulin from your pancreas gland. Insulin’s job is to get sugar out of the bloodstream (where a raised blood sugar, as in type 2 diabetes, does damage over time) and into the muscle, liver and fat cells.
When insulin is high (as after a carby meal or snack), tryptophan (an amino acid from food) can pass from the bloodstream into the brain more easily. Tryptophan is then converted into serotonin. So, in short, when we eat sugar, on top of the dopamine hit already described, we also get a boost of serotonin and a feeling of wellbeing and comfort. Most people recognise that sugary foods will lead to these feelings and can start to use food for emotion- al reasons. However, the brain will also down regulate serotonin receptors, meaning, over time, we need more sugar to get the same effect.
I hope you can see the desperate trap that carbohydrate addiction can become. We are left depleted emotionally at a biological level but also psychologically and behaviourally. People also suffer from aversive physical withdrawal symptoms when they can’t access sugary foods. Shakiness, irritability, sleep problems, headache, fatigue and nausea are commonly experienced but resolve on consum- ing something high in carbohydrate. The sugar fix. Most people never go long enough to get through the withdrawal phase because of this. Another part of the trap!
The fact that sugar stimulates the survival and primitive parts of the brain means that your logical, thinking brain is overridden.
This is why we struggle to resist cravings with willpower. You need to act your way out of addiction over time with new habits, because you can’t think your way out of it. As a psychologist I could never understand how I would decide not to eat biscuits in the morning but then helplessly watch my hand reaching for them in the afternoon. It wasn’t my fault and it isn’t yours. It is biology in action. This information will be your power.
What do I eat now?
Here’s a good place to start. (Click for more)