I guess I mixed up terms. A full load would be 16 credit hours in the States. That could be 4 or more classes depending on how many credits each class is worth. Full time is only 12 credit hours.
To answer your question, I would think it doesn't matter. For example, I completed the Georgetown University Post-Baccalaureate Pre-Medical Program last year. To be considered full time in the program I was only required to take 2 classes per semester, even though I took more than this. The program director said the most important thing is to get A's, not your work load.
However, during the Georgetown program I volunteered and did research. I think the committee would look at how you are using your time rather than how many classes you are taking if your grades are decent. If you aren't taking a full load, did you sit around watching TV and playing video games? Or, did you spend your time tutoring other students, volunteering, and doing research? That's at least what I have heard from other admission committees.
