Water

Water has been shown to boost  metabolism by as much as 30%.  This is due to the fact that the  body  heats up  water after you drink it.  It occurs pretty much all the time however it is  most effective when you drink water on an empty stomach— (the best time is when you first wake up in the morning because your stomach is empty after 7 or 8 hours of fasting) or 3 to 4 hours after eating.  A trick I always use is drink a full glass of water or 500 ml bottle  before I start eating since the process occurs within 10 minutes.  This way my metabolism is already up  before I eat.

Note:  To calculate how much water you should drink divide your weight by 2 and that’s how many ounces  of water you should be drinking a day