You'd make a stronger counter argument if you provided evidence of your claim ("the less preservatives the food is stuffed with, the better it is for the consum

You'd make a stronger counter argument if you provided evidence of your claim ("the less preservatives the food is stuffed with, the better it is for the consumer") rather than just saying people should trust you because you studied diets for 2 years. Vitamin C is a preservative, are you arguing that it's bad for you ? Or are you saying some specific subset of preservatives can be bad for you ? - in which case you should be specific about which preservatives you're talking about rather than talking about them in a generic way.