Code:
awk '
FNR == NR {T[$1,$2] = $0
sub ("^" $1 FS $2 FS $3, "", T[$1,$2])
next
}
$1,$4 in T {print $0 T[$1,$4]
}
' FS=, file2 file1
NAME, FAV_FOOD, FAV_DRINK, ID, GENDER, COUNTRY
Bob, Fish, Coke, 1, M , 31, Ireland
Lisa, Rice, Water, 2, F , 22, UK
Jenny, Noodle, Tea, 3, F , 18, France
Ken, Pizza, Coffee, 4, M , 12, Iceland
Lisa, Cake, Milk, 2, F , 22, UK
Ken, Sandwich, Juice, 4, M , 12, Iceland