Guiding Stars also bases their ratings on 100g of the food, which to me is crazy.

Who eats a 100 g serving of dried oregano? For reference, a typical grocery store bottle of oregano contains about 3/4 oz (21 g) of oregano - 100 g of oregano would be almost 5 of those bottles. The typical recipe only calls for a tsp or two of oregano, and that's almost always divided between at least 4 servings.

The typical 4-serving meat entree recipe calls for four 4 oz pieces of meat - but 100 g is only about 3-1/2 oz. So if you're depending on the accuracy of100 g servings, you either need to remove 1/2 oz from each piece of meat, or figure out how much more of each nutrient that extra 1/2 oz provides.

Nutrivore or any other nutrition scoring systems that use a 100 g standard to score every food really confuses the whole nutrition issue, making it way too complicated. Does it really help all that much to know that a food has a really high selenium or chromium content per 100 g if the typical serving is only 1 g?

And that's before you even get into the issue of satiety of one type of food compared to another, or the necessity of essential fatty acids needed in your diet in order to properly absorb the micronutrients in other foods.