A healthy adult should not exceed 200 mg of caffeine at one time, and 400 throughout the day. Excessive consumption can lead to risk of miscarriage or problems with fetal development.
People prone to sleep disorders should also limit their consumption, as should those prone to digestive disorders, such as heartburn, gastritis or reflux. Espresso contains less caffeine than filter coffee, so you can drink more espressos than filter coffees during the day, says Professor Philippe Pouillart.