"Nutrition information completed from another source"
I'm not exactly sure of the feature's actual name, but I would have a question about the feature from the title, the feature that allows a food with incomplete nutrition information to be completed from the nutrition information of a food that is ostensibly the same, found in the better databases like NCCDB. I think the feature is absolutely great in theory: it allows someone to use the exact nutrition info that is on the label of the food they have in their hands, while providing a "best educated guess" of what the missing nutrients on the label would be. But how does it work exactly?
For example, here I have a carton of Silk Unsweetened Soy Milk, from Canada. The label says that it contains 90 calories, 8 grams of protein, 100mcg of vitamin A and 1mg of zinc per cup. For some reason, "Silk Unsweetened Soy Milk" in the NCCDB shows 71 calories, 7 grams of protein, 150mcg of vitamin A and 0.4mg of zinc. Those are annoying differences, ranging from 10% to over 50% more or less for certain nutrients. My understanding would be that the NCCDB info is based on the US version of the product. Ideally, I would like to use what I think is the "more accurate" nutrition info for what I'm actually consuming, the Canadian version of the product, and then fill the missing info with whatever's in the NCCDB. But you can see that something's weird with that feature for the missing info:
For some reason it shows only 92.4 grams of water for a cup. That product is obviously mostly water and it "should" show something closer to the 225.5 grams of water that the generic soy milk in the NCCDB shows (the product used to complete the missing info). And that's not the only probably inaccurate info, it is pretty much all of the originally missing info. For example, the NCCDB product shows 0.5g of leucine for 8.7 grams of protein. For some reason, the Canadian Silk Soy Milk showing 8 grams of protein, when using the NCCDB to fill in the missing info, shows 0.2 grams of leucine. How does that make any sense? I would expect that that "missing info" feature would simply look up the NCCDB for the same "portion" (1 cup) and fill the missing info from that. But it seems like that's not what it's doing, it's doing something more complicated, something that might sound like it would fill the missing info more accurately, on paper, but in practice fills the missing info with what seems like nonsense (at least at first glance?). So how does the feature work, how does it determine how much nutrient it is going to use for the missing info? Would it be better to simply always add only the NCCDB foods to one's diary?
Thanks