How many grams of natural sugars a day should i be eating as a maximum when trying to lose weight?

It depends...: This is a good question with no simple answer. More important than the amount of natural sugars is the degree to which they will raise your sugar, measured as glycemic index/load & carohydrrate density. See http://www.Hsph.Harvard.Edu/nutritionsource/carbohydrates-full-story/ & http://www.Mendosa.Com/gi.Htm & http://www.Huffingtonpost.Com/andrew-weil-md/carbohydrates-weight-loss_b_1937312.Html.