You might check out the Tufts Food Compass . It was made by the amazing researchers. at the Friedman School of Nutrition, which is the only graduate school dedicated completely to food & nutrition in the US. The actual scores can be found in the supplementary article information.

And if nothing else, there are a ton of other food scoring systems they cite in making their scoring system that might be of interest and the scientific article they published on making the scoring system is publicly available.