http://www.health.uci.edu/services/nutrition/nutrition.html#caffeine

Yes. Coffee is safe if you consume it in moderate amounts. For most healthy adults, moderate amounts of caffeine – 200 to 300 milligrams a day, or about two to three cups of coffee – pose no physical problems (American Dietetic Association).
Caffeine is a mild stimulant, which is found in the leaves, fruits, and seeds of many plants. Tea leaves, coffee and cocoa beans, as well as kola nuts all contain caffeine.
Caffeine can be found in coffee, soda, chocolate, some pain relievers, cold remedies, weight control aids, and various prescription medications.

http://www.health.uci.edu/services/nutrition/nutrition.html#caffeine

Tame the tension with exercise and advanced planning

While a great motivator, stress isn’t so great for your health.
When under stress, people don’t turn to granola for comfort. Instead, they skip the gym, head for a double cheeseburger and fries at the nearest fast food joint and have a smoke, according to a 2006 random national survey of more than 2,000 people conducted by the American Psychological Association. Of those questioned, 59 percent said work was a leading source of stress and 47 percent said they were concerned about stress in their lives.
It’s also not great for the bottom line, often resulting in absenteeism, lowered productivity, turnover and health claims. Research has shown that people who are stressed out are more likely to experience hypertension, anxiety or depression and obesity.
But some businesses, particularly those small- to mid-sized, are hesitant to hire stress relief experts or pay for workshops aimed at helping employees find balance in their lives.
Find more ways to relieve the workplace stress at MSNBC.com:

http://www.msnbc.msn.com/id/18440216/wid/11915773