Evaluate the amount of caffeine that you are taking in on a daily basis. The best way to know what you are drinking is to keep a food journal for a week. Assess where your caffeine is coming from whether it is from soda, energy drinks, coffee and/or medications. Taking in too much caffeine can cause body jitters and restlessness. Many nutritional organizations and doctors believe that two to four cups of coffee is safe. However the sugar found in sodas, energy drinks and that is added to coffee can also cause sleep issues.