Boost daily energy expenditure and metabolism

The main reason people are overweight is because their basal metabolic rate (BMR) is lower than it should be for the amount of food they consume each day.  BMR is the rate at which your body burns calories to perform its normal functions of digestion, circulation, breathing, etc. This means that they burn fewer calories 24 hours a day. Obviously, over a period of months, this adds up to stored fat.

Get active!  Aerobic exercise for more than thirty minutes not only burns calories but also keeps your metabolism high for several hours afterwards. The best time for exercise is in the morning as it will help kick start your metabolism for the day. If you can do 30 to 60 minutes of aerobic exercise almost every day your metabolism will soar. Interval training would help even more.

Eat little and often. Small and regular meals throughout the day will keep your metabolism high. If you eat the same amount of food in just one or two large meals as you do in five or six mini-meals and snacks you will burn fewer calories. This is because your metabolism slows down between meals. Never skip meals to save calories. Having a low-calorie snack will work much better and will also stop you falling on the nearest chocolate bar later in the day.

Drink Coffee.  Caffeine speeds up your heart rate and the faster your heart rate the more calories you burn. Not great if you have heart problems or difficulty getting to sleep however!
Drink Green Tea.  The photochemical in green tea are supposed to raise metabolism slightly by causing your brain and nervous system to run more quickly. Although not many sizable and conclusive studies have been done on this to date, drinking green tea rather than milky coffee or other calorie-laden beverages will definitely increase BMR.

Build those muscles. Muscles burn calories even when you're resting. For every kilo of muscle you add, you burn about 50 extra calories a day without taking any more exercise. So it's a great idea to include some resistance or weight training in your exercise regime. Twenty minutes three times a week is enough to make a big difference in your metabolic rate as well as the shape of your body.

Watch the alcohol.  On top of the empty calories that alcohol contains, it also has a dehydrating effect, which slows down your body’s thermic metabolism. Alcohol tends to inhibit the process of metabolizing fat too, which can lower   your basal metabolism. And there's not much chance of you wanting to exercise after all that booze so it'll have an effect on your activity metabolism too. Bad news all round!