Cravings build quickly, interrupting other activities. Often the addictive food and drink is not satisfying, and the most dysfunctional people keep eating and drinking with only the briefest interruptions. The gratification is short-lived and is followed by decreasing energy, irritability and renewed cravings. The nicotine loop in smokers may be in the range of 20 minutes. The timing of food loops is variable and ranges from minutes to hours.
Addictive substances are good at inducing recursive loops.
Once an addictive substance is added to the list of chemicals in your environment you need to get every day, you are at risk plunging into a withdrawal state if the supply is cut off. Food addiction is easier and cheaper than heroin addiction, but it may be more difficult to resolve since the supply may never be cut off except by heroic abstention. Often, patients experience acute withdrawal symptoms beginning within a few hours of not eating their food fix. Some will tell us they need to eat every 2 hours. They become restless, irritable and may go to considerable trouble to get their fix if it is not immediately available.