Israeli security is tight, yes, but you can bring your own food and liquids from home onto the flight in Israel. Israelis tend to bring their own food from home to take on budget flights, as the airport choices are limited and overpriced. You can also bring liquid souvenirs with you (alcohol not from the Duty Free / olive oil, etc.) in your hand luggage from Israel, as long as you're flying directly home or not going through an airport that'll make you go through security again.