Staying hydrated is essential for maintaining not only a healthy lifestyle but also healthy and well nourished skin and although water is the best choice when it comes to what to drink on a daily basis most healthy people can gain enough fluids from their usual array of beverages including fizzy drinks, fruit juice, milk and milk alternatives.
Contrary to popular belief caffeinated drinks such as coffee, energy drinks and tea don’t cause dehydration in your skin or body when drank in moderation. Research has shown that healthy people can consume up to about four 8 ounce cups of coffee per day before the caffeine intake can start to lead to dehydration however it is vitally important to remember that too much caffeine can have detrimental effects not only to the quality and wellbeing of your skin but also to your health in a number of other subversive ways.
Excessive caffeine intake can lead to a lack of concentration, jitters, increased heart rate and a number of more server undesirable side effects such as stomach irritation (particularly within those who suffer from IBS), exacerbation of weak bone disorders such as osteoporosis and its also been seen to increase the pressure inside the eye after drinking which may over time lead to eye damage and such conditions as glaucoma so consuming it in 'moderation' is key.
In short, a standard intake of caffeine does not cause dehydration and can in fact contribute to your daily intake of fluids, however by no means should this be your main source of fluids per day. Drinking plenty of non caffeinated drinks is the best way to keep you hydrated but the odd shot of coffee or tea will not be detrimental to your water count.