Food addiction is a curious addiction. For years, it has been argued that eating could not possibly be an addiction, since it did to contain a chemically stimulating component. But recent studies have shown that there is indeed one.
It is hard to classify Food Addiction, just as it is hard to classify sex addiction. Someone who overeats may not be a food addict. But, someone who is underweight may be thinking only about their next meal and how later they will binge. How then, does food addiction start and what causes it to be addictive?
As with most other addictions, it comes down to the reward pathway and serotonin. When we eat food, specifically sugars or carbohydrates (which break down into sugar), our body produces insulin to help move the nutrients throughout our body. One very common amino acid, called tryptophan, is not carried by the insulin. Tryptophan converts into serotonin.
The increase in serotonin levels triggers a good feeling, or a "euphoric feeling". This increase in serotonin may trigger the chemical reactions in the reward pathway. Thus, in the end, the body will begin to crave the sugars again to reach that euphoria, or that high. The brain will try and reinforce this behavior, Leading to food addiction.