Med school students will most likely have more loans than UG because:
1) less merit and need-based financial aid available. At most schools, these are supported by private donations similar to how many undergrad funding is supported. And since med school is much smaller group of students and more importantly is expected to have a much high future income than most people with just a BS/BA, so most big donors would rather donate to undergrad scholarships. Similar principle applies to why federal loan interest rates are also higher for grad/professional students and are now all unsubsidized, and why many state-wide tuition scholarship programs that easily cover full tuition or their public undergrads (eg HOPE/Zell Miller in Georgia, Bright Futures in Florida, Cal Grants in California) don't extend to grad/professional students. The only two major COA scholarships I know of are the military ones and the ones for MD/PhD students. Obviously, going either route is not for everyone so wouldn't try go for either just for the full scholarship. Many schools, especially private ones, will still have some merit or need-based aid (many lower tier public schools have little aid since their tuition is already very cheap and they are not as well known so they get less donations). In general, the top tier schools give out their aid on mostly a need basis using the "unit loan" model (where you you have to take out a certain amount of loan every year before you can get any of their grant/scholarship aid), while mid and lower tier schools will give out more aid on a merit basis (they want to attract above-average students to go there instead of a higher tier school).
2) Most parents are less financially supportive than in undergrad for similar reasons as mentioned above, especially if their child went to an expensive private undergrad with little aid. Then again, since most students getting into med school come from upper middle class backgrounds, it's not uncommon for some parents to still pay their entire COA for med school (on top of undergrad). But if that's not a possibility, you'll probably have to borrow at least some.
3) COA tends to be a bit higher than undergrad since it is generally more expensive to train med students (due to the specialized facilities and mentoring required), and most estimate than COA for a full year due to a lack of summer breaks after 1st year (while most undergrads only consider living costs for about 8-9 months out of the year). But this can vary significantly. The $80k/year mentioned is probably at a private school in a high cost of living city. Tuition at some state schools may be as little as $15k (eg many of the Texas schools), and if in an area with low cost of living the total COA may only be $35-40k. At other state schools like UVA it may be $48k just for in-state. It really depends on how much the state chooses to fund their future physicians...
