What they all said. And a note on willpower at starbucks: have a look at the back of the syrup bottles. It tells you how much calories are in one pump. Now multiply the number of pumps of syrup you get in a drink by the number of partner beverages you consume in an average shift. Personally, I alternate between tea and plain old water. Just because it's free doesn't mean you should drink it. Also avoid the lemonade, as it has a lot more sugar than your average lemonade.
Every little bit helps!
