TOLERANCE
One of the criteria for substance use disorder is tolerance, which means that a person needs to consume more of a substance to achieve the same effects or experiences less effects with the same amount of substance. Tolerance results in the person needing to eat more food, or more specific foods, or more individually identified trigger foods over time to achieve the same rewarding or pleasurable effects.
When a person repeatedly does something that releases dopamine in the reward system, such as smoking a cigarette or eating a Snickers bar, dopamine receptors can start to down regulate. If the brain observes that the amount of dopamine is too high, it begins removing dopamine receptors to keep things balanced. When there are fewer receptors, more dopamine is needed to reach the same effect, which causes people to start eating more of their individually identified trigger food to reach the same level of reward as before. This is called tolerance.
WITHDRAWAL
Withdrawal is when a person experiences unpleasant symptoms when they stop using a substance or uses the substance to avoid those symptoms. For food addiction, this could mean that a person feels anxious, irritable, or depressed when they abstain from certain foods or consumes those foods to relieve their negative mood .
If there are fewer dopamine receptors, the person will have very little dopamine activity and start to feel unhappy when they don’t get their individual identified trigger food “fix.” This is called withdrawal.
Frequent consumption of individually identified trigger foods may lead to dopamine tolerance. This means that a person will have to eat even more of their individually identified trigger foods to avoid going into withdrawal.
Tolerance and withdrawal are associated with addictive disorders.