Standalone app's memory increases unexpectedly

I am running a study code on a little microcontroller. What I observe is that when the code is running via Matlab, everything is OK. But when I compile the very same code, then the apps/program's memory in Windows 10 is increasing quite fast when running. I have tried to google it, but did not find similar problem. Why could that happen? How could I debug it? Thanks.

[grega]

I sill haven't solved it. I have tested the code with the "whos" function but when running the code, all the variables sizes remain the same, so the code seems to be OK not having some variables which size increases. Any ideas?