I don't have a lot of value to add to this item, but I don't want you to miss it.
Turns out that schools that serve high-poverty populations that want to improve their test scores may want to pay closer attention to when SNAP benefits arrive. The Supplemental Nutrition Assistance Program is what we used to call "food stamps," and researchers a have determined that SNAP is just as important to your test scores as a few rounds of test prep.
Chad D. Cotti (University of Wisconsin), John Gordanier (University of South Carolina), and Orgul D. Ozturk (University of South Carolina) looked at standardized test scores plotted against the SNAP benefits cycle and discovered, lo and behold, that students who tested during the final weeks of the benefit cycle (when families have typically used up the benefits and are making do with less food)-- those students get lower scores. There's also an effect when the benefits arrive within the four days before testing, and that score-lowering effect primarily hits African-American males. The researchers suggest it's a weekend thing.
The data was from testing in South Carolina from 2000-2012. It involves some equations that I don't understand and a great deal of economist jargon. If a student's family receives benefits 26 days before testing, the researchers find the "student performs between 14 and 4.5 hundredths of a standard deviation" worse than they would have on a better day.
So if you'd like a paper that shows that 1) SNAP has positive benefits and 2) Big Standardized Tests measure factors that have nothing to do with educational achievement, here you go. Because that's where we are now-- needing actual proof that students do better when they are well fed.