People have been urged to be careful about their daily intake of a common food ingredient . Experts at health test kit provider PocDoc have warned that people may be consuming more caffeine than they think, especially if you think you're only getting the stimulant in your coffee. Dr Kate Bunyan, lead clinical director at the group, warned there is a "common misconception" that your daily espresso or americano is your sole source of caffeine. She said: "Many people underestimate how easily