It is true to an extent that certain foods are more addictive than others and this tends to be related to the brain’s reward system. For example, when you consume food, the brain releases chemicals that inform you that you’re making a good choice by providing your body with fuel. One of the well-known chemicals that is released as part of this reward system is dopamine, which is associated with a feeling of well-being or satisfaction.
The addictive part occurs when you repeatedly consume these unhealthy foods that give you such spikes in dopamine.
A 2016 study from the University of Michigan suggested that unhealthy foods or junk food cause this sense of reward in far higher quantities than natural, whole foods. Healthy and natural foods such as salmon or broccoli tend to cause a moderate release of these reward chemicals whereas unhealthier, sugary treats, such as ice cream, tend to cause a much faster release of chemicals such as dopamine, giving you a greater, albeit briefer sense of satisfaction.
The addictive part occurs when you repeatedly consume these unhealthy foods that give you such spikes in dopamine. The brain starts to recognise that the dopamine levels have become too high and begins to remove dopamine receptors to maintain a balance. When the level of dopamine receptors are lower, you need more of the unhealthy foods that you find rewarding to reach the same levels of dopamine as previously.
Another point you should also consider is what triggers such cravings. Often, triggers can be simple — such as smelling your favourite unhealthy treat or visiting a particular destination you associate with unhealthy food. However, triggers can also include factors such as stress levels or anxiety, so you should be aware of the affect that your psychological well-being may be having on your eating decisions.