obviously, my biggest dilemma here is deciding which will actually improve my chances. If I apply ED, I have a lower GPA, but I’m in a smaller applicant pool (though they’re all strong applicants). If I apply RD, I have a slightly higher GPA, potentially better test scores, but I’m competing against so many more people.
I took the ACT again last week, and I’m taking my subject tests (Math II + Bio) for the first time in October.
I see your difficulty as this: your weakness is math with a 26 on that section of the ACT. Looking at course requirements for the Food Science major, I see a lot of math & science classes that typically correlate to math skills (chem / Physics). https://foodscience.cals.cornell.edu/sites/foodscience.cals.cornell.edu/files/shared/Food%20Science%20Option%208-19-2014.pdf IMHO, your profile appears more suited to a major that is more correlated with verbal prowess, however I am obviously not on the admissions committee.
I agree with @csdad however I do believe ED gives applicants a slight edge. What you hope for is an acceptance, obviously, but would be OK with a deferral into RD. What you risk ED is a flat out rejection. Is your essay strong? Because that is an extremely important part of your application.
A 31 isn’t a bad score and it needs to be put into context within the college/program you are applying to. You should check out the Common Data Set for Cornell to see where you fall.