Final answer:
To sober up after drinking, a person must simply wait for their liver to metabolize the alcohol, which takes around five hours for a legally intoxicated individual. Eating a heavy meal does not effectively reduce alcohol toxicity or speed up sobriety.
Step-by-step explanation:
If a person has been drinking, the only thing that can sober them up is time. The liver must metabolize the ingested alcohol, and this process cannot be sped up by outside means such as drinking coffee or eating. Considering the alcohol metabolism rate and excretion, it typically takes at least five hours for a legally intoxicated person (with a BAC of 0.08) to sober up. It's important to understand that factors like age, sex, pre-existing health conditions, and individual metabolism can affect the BAC and how quickly a person sobers up.
While it might be a common belief that eating a heavy meal can help someone sober up, this is not effective in reducing alcohol toxicity. Food does not decrease the alcohol concentration in the blood; it only affects the absorption rate of alcohol into the bloodstream if consumed beforehand. Therefore, once alcohol is in the system, only time will allow the body to process and eliminate it.