@monjmom - The advice that we got when our D was a freshman (from both posters here and UMD Dining itself) was to pick the lowest cost plan, which we did. And it worked well for my D. However, this year the plans have changed. I still tend to think that the Base Plan will be adequate, but you may want also consider the Base Plus Plan. If you attend an Admitted Student Open House. you be able to get some good advice there. Also be aware that you can supplement the Dining Plan with a Terp Express account, which is like a re-loadable debit account tied to the Student ID card.
Here is the Terp Express link