Protein foods have higher than average dietary thermogenic effects, eating foods produces heat, which equals calorie usage of around 10% of total energy expenditure.nThe effect-up to 25% of such meal's calories may burnt off due the thermogenic.nnIn theory this means that a diet consisting of high levels of protein would results in considerable speeding up of to the metabolism.nIn practice, however, this isn't such a good idea, as a high-protein diet can stress the kidneys and liver, is linked with loss of bone calcium and may also be linked to higher blood pressure levels.nAlso a high-protein diet may cause shortfall of nutrients present in other types of food.nnSome protein foods contain a fatty acid called conjugated linoleic acid(CLA), which can help speed fat loss, and calcium (e.g.in dairy products) seems to help MR.In one Tennessee University trial, volunteers who ate a calcium-rich diet loss 20% more body fat than people who had a lower -calcium diet with the same number of calories.nnSpices, particularly chili, appear to raise metabolic rate by up 50%-an effect that lasts for up to three hours. This appears to be because th heart rate increases when spices are eaten . Several clinical research studies have found evidence of this effect in variety of ways, so this is one metabolism-boosting trick you can use without guilt.nnCaffeine-containing drinks increase the metabolism by arousing the nervous system's flight response and levels of adrenaline (epinephrine), increasing heart rate and 'fidget factor'. Caffeine equivalent to 2.5 cups of coffee can also increase endurance during moderate exercise.nCoffee and colas are two of the drinks highest in caffeine. However, more than three or four cups of high-caffeine coffee a day is not recommended, because of possible adverse effects on health. Caffeine is also found in tea, chocolate and range of manufactured drinks, including some sport drinks.nnInterestingly, green tea also appears to stimulate the metabolism without increasing the heart rate. A swiss study found that people who took extract of green tea burned significantly more calories than people who didn't.nThe phytochemical flavonoids in green tea seem to affect the 'energy' hormone noradrenaline (norepinephrine) in the body, which then speeds fat oxidation.nnIf you have an iodine deficiency which may result in poor functioning of your thyroid gland, production of the hormone thyroxine may be low. This may lower your metabolic rate, and a diet rich in seagreens such as dulse, kombu or wakame, seafood and milk raise your iodine levels and improve thyroid function and metabolism.nnIf your thyroid function is normal, however, these foods won't help. (A blood test via your doctor can easily check whether your thyroid function normal or not)