Caffeine stimulates the central nervous system, so when you need to get going in the morning or need an afternoon pick-me-up, caffeine usually gets the job done by making you more alert. Most healthy adults can tolerate 200 to 300 mg of coffee per day, which is about 2 to 4 cups. However, you might find it necessary to curtail or eliminate your caffeine consumption if your circumstances change or if you cannot tolerate that level of caffeine.
Caffeine is not limited to coffee; it is also in tea, soda, energy drinks, chocolate and some over-the-counter medicines such as aspirin and pain relievers. When figuring your total caffeine usage per day, factor all the caffeine products you consume. Even a healthy adult can suffer side effects of headaches, anxiety, insomnia, irritability, rapid heartbeat, upset stomach and restlessness from too much caffeine consumption, which is more than 500 to 600 mg a day. If you consume more than that, you should cut back.
The caffeine in coffee and tea varies depending on how strongly it is brewed, but you can follow a general guide. An 8-oz. cup of brewed coffee contains 95 to 200 mg of caffeine; 8-oz. of black tea contains 14 to 61 mg of caffeine; 12 oz. of a cola drink contains 35 mg of caffeine; and an 8 oz. energy drink contains 70 to 80 mg of caffeine, depending on the brand. A chocolate bar contains about 31 mg of caffeine, and medicines vary between 64 and 200 mg of caffeine.
Situations to Consume Less
The smaller the person is the greater the effect of caffeine. Therefore, on average, people with smaller body mass feel caffeine side effects after consuming less daily caffeine than larger people do. Because caffeine is a diuretic, it might cause dehydration. To be safe, limit caffeine intake when you are likely to sweat during heavy exercise or when the weather is hot. The effects of caffeine vary greatly from person to person. If you experience negative effects from caffeine, reduce or eliminate your intake.
If you have heart problems or are on certain supplements or medications that caffeine interacts with, you might want to limit your caffeine intake. Check with your doctor to determine a safe level for you. Pregnancy may require you to cut back on caffeine consumption because caffeine increases your heart rate and blood pressure, effects you want to avoid during pregnancy. Caffeine crosses the placenta and disrupts the baby’s sleep pattern. Pregnant women should limit caffeine intake to 200 mg per day or less.