i read somewhere yesterday: "you don't catch a flu, you eat it."
throwing in vitamin C might help (it gives me sleepleness, should not be mixed with fat or empty stomach) but it's not as powerfull as eating a nutrient dense (fatty) diet with huge portions of vegetables. how about 2 herrings, 125 g of macademia nuts, coconut fat & 750g asian wok mix vegs. coconut fat is said to kill bugs, btw. that's what i had today for breakfast (i just eat once a day right now, testing how that works for my metabolism, right now my metabolism is cooking!). thats 1700 kcal, 40 g carbs, 70g protein, 140 g fat. nothing evil can survive in this bomb of goodness. but eating too little carbs or too much protein can make vulnerable, in case it makes you acidic (dry mouth). body needs to be adapted.
edit: i just noticed this thread isnt about the flu, but about cold weather.
okay, but metabolism is still food related. as i said, i am cooking.