Your metabolism defines how quickly you burn up calories and carbs each day. How can you raise your metabolism to burn more energy?

Drink Water
Probably the most important thing you can do to keep your metabolism working as quickly as it can is to drink ample water every day. Just about every part of your metabolism needs water to work properly. Drink at least 8 glasses each day. Avoid soda and caffeine - both serve to flush water out of your system.

Eat Small, Regular Meals
If you go too long between meals, your body will think a famine has hit and will begin to conserve your remaining energy. It will reduce your metabolism to help you survive this problem. You need to keep the food coming in - but healthy food of course!

Eat Complex / Fiber Filled Foods
Digestion takes energy. If you just ate pure sugar, your body could instantly turn that into fat with no problem. However, if you ate celery, it could literally take more energy for your body to digest all that fiber than the celery provided! Meaning you could LOSE weight simply by eating celery. Protein is also that way - it is a lot of work for your body to turn protein into fuel. It can actually take up to 30 calories of energy to process 100 calories of protein you eat!

Avoid Sugars
If you eat sugar or high carb food, it causes a temporary blood sugar spike, and then your blood sugar plummets once that 'wave' is done. This causes your metabolism to go into a funk and stop processing foods properly. It is why you get hungry again after eating Chinese food. You get the quick boost, then the deep trough that your body thinks is a sign of trouble. For ideal high metabolism, you want a smooth, constant flow of energy and an even blood sugar level.

Drink Cold Water
I find this tip to be a little silly, but heck, every tiny bit helps! If you drink a glass of cold water, your body has to spend about 12 calories to warm it up. If you're drinking your 8 glasses of water a day, that's about 100 calories. It's not an exercise program - but every bit helps!

Spices
Some really small studies have shown the eating spicy foods boost your metabolism for about 30 minutes. However, the boost is so small (20% at most) for such a short period of time that it's not really a way to get a measureable impact on your weight.