use strict;
use warnings;
use Data::Dumper;

my @fields = qw( name email );
my %results;
print "Before: ", Dumper(\%results);
@results{@fields} = ();
print "After: ", Dumper(\%results);

__END__

Before: $VAR1 = {};

After: $VAR1 = {
          'email' => undef,
          'name' => undef
        };