大概是多少? 这取决于你身体的新陈代谢机能，正常情况下体重为70kg的成年人饮用量每天小于500mg，建议是每天4-6杯咖啡300-400mg左右的摄入量。

　　How much is too much? It depends on how fast your body metabolises caffeine, but as a general rule: "A high dose of caffeine is 500mg per day, based on a 70kg adult, which works out at six to eight cups of instant coffee," says Karen Dickinson, of Body Acoustics Health and Sports Nutrition. "A moderate dose is 300 to 400mg per day; four to six cups."

　　那么常见的饮品中，都含有多少的咖啡因呢?以下是每100毫升单位的咖啡因含量数据：

　　Here's how much caffeine (in mg per 100ml) is contained in some of your favourite beverages...

　　可可 Coca-Cola: 9.7 mg/100ml

　　速溶咖啡 Instant Coffee: 24.1 mg/100ml

　　浓缩咖啡 Espresso Coffee: 173.6 mg/100ml

　　手冲纯咖啡(黑咖啡) Plunger Coffee: 45.4 mg/100ml

　　低咖啡因咖啡 Decaf (instant) Coffee: 1.1 mg/100ml

　　健怡可乐 Diet Coke: 12.7 mg/100ml

　　能量饮料Lift Plus: 14.5 mg/100ml

　　能量饮料 百事可乐 Pepsi Max: 19.4 mg/100ml

　　能量饮料 无糖百事可乐 Diet Pepsi: 10.1 mg/100ml

　　能量饮料 红牛 Red Bull: 32 mg/100ml

　　能量饮料 红牛能量饮料 Red Bull Energy Shot: 133.3 mg/100ml

　　茶 Tea (white): 6.3 mg/100ml

　　这个是澳洲品牌的能量饮料，还没进入中国 V Pocket Rocket Energy Shot: 266.5 mg/100ml