Benefits:

• The most common beverages consumed after water include tea and coffee. The popular drinks contain caffeine that acts as a stimulant of the central nervous system. Caffeine has been studied to reduce fatigue, drowsiness, improve concentration, and improve motor coordination. In addition to the same, coffee beans and tea leaves also contain antioxidants that lower the risk of cardiovascular diseases and cancers. Intake of antioxidants also prevents damage caused to the body due to oxidation. 
• Dark chocolates made up of 60% cacao contain approximately 20 mg of caffeine in every 1.5 ounces of serving. Dark chocolates are also a rich source of caffeine and comprise of all the health benefits stated above.

The problem and the solution:

• The caffeine present in the tea, coffee, or dark chocolates has a half-life of 5 to 6 hours. It means that only after 5 to 6 hours, the body can effectively eliminate one-half of the caffeine consumed. So, ideally, the consumption of caffeinated substances is recommended 8 hours before bedtime. 
• That would ensure that the deep sleep remains undisturbed. So that the regeneration and restoration activity of the GH remains undisturbed. 
• Caffeinated beverages must not be consumed with sugar, but can be consumed with substitutes such as honey or jiggery or dates. Addition of sugar eliminates the beneficial properties from caffeine.