4 ms·

TL; DR: these recommended “safe” levels of caffeine are just statistical averages over the population. Some people tolerate caffeine and can ingest large quant

• drzaiusapelord 14y ago
  This is a good point. I get a little jittery from one diet coke and two diet cokes makes me feel really sped up and gives me insomnia. A cup of coffee is almost unbearable. I'll drink a tea for a little caffeine, but that's about it. I have no idea how people tolerate drinks with multiple shots of espresso. Tolerance must vary wildly between people.
  • ikawe 14y ago
    My tolerance has changed a lot going from my early 20's to my late 20's. I used to regularly drink 8 cups a day, but now start to feel awful after 2. I think its a combination of losing the acquired tolerance, increasing a latent sensitivity, and more awareness of my physiology.
    • prawks 14y ago
      Metabolism is also a factor, which begins to slow in many people's late 20's.
• mynameismiek 14y ago
  Genetics play a role. I had 23 and Me sequence my DNA two years ago and one of the things they check for is caffeine tolerance. I don't have it. I can drink a 20oz Mountain Dew for lunch (11:30 AM) and it will keep me awake till at least 10:30 PM if not 11 or 12 or even later, without fail. Some people do not metabolize it. Often, I'll get jitters after a single cup of coffee. I restrict my caffeine intake because of this.