Not eating for a few hours won't put your body into "starvation mode." That would only happen if you were actually starving. It is true that eating fewer calories can slow the metabolism. Anyway, there are a lot of websites about it. Doing a quick google search will yeild a lot of results. Here is one webstie i found:

http://www.naturalphysiques.com/faq/279.html

Starvation mode happens after days and days of not eating enough, not hours. Unfortunately that term is thrown around here way too often and gets people all paranoid. I rarely snack between meals and am having no problems losing weight.

No.  Simpy not eating won't cause you to starve.  "Starvation Mode" takes months to acheive and it's more set at a severe caloric restrcition.  IF you are trying to help your metabolism though you should eat between meals.  You east failry large meals three times a day because you have be waiting so much time in between to eat!  So when you do eat 6 hours five hours later you are famished and may binge a little.  OS what if you are staying within your caloric needs, if you are not helping your metabolism by feeding your body fuel every few hours it simply wont help.  You can divide what you eat in a day over five or even six small meals.  Or three small main meals, and three snacks throughout your day, and trust me you wont be starving at main meals, but actually your body will be looking for fuel every few hours, and this is a sign your metabolsim is revving.  If you exercise too...waiting for a long period of time to eat afterwards can rob your body of it's much need nutrients.  You need of cours elots of water...but also you have to replenish your carbs and proteins.  IF you did a massive strength workout then have a protein bar after wards ro a shake or a cup of tuna, something of the sort.  If you did a big cardio workout, a small portion of complex carbs and light fruit and water would be appropriate.  Then these would factor in a small snacks inbetween meals.  Hope i didn't confuse you.

"Starvation Mode" Here is what "The British Medical Association" which is the body of "The Highest Qualified Doctors and Specialists" in the UK say about it, they call it "Fasting"

Quote: Without food, the energy needed to maintain essential body processes is supplied by substances stored in the body tissue.

About six hours after your last meal, the body starts to use glycogen (a carbohydrate stored in the liver and muscles). This continues for about 24hrs, after which the body adapts to obtaining energy from stored fat and from protein obtained from the breaking down of muscles.

After a few days, most of the energy is obtained from fat, although some continues to come from muscle breakdown. If fasting continues, the body's metabolism slows to conserve energy. As a result of this slowdown, the fat and protein from muscles are consumed more slowly.

In initial stages of fasting, weight loss is rapid. Later it slows, not only because metabolism slows down, but because the body starts to conserve its salt supply, which causes water retention.

In prolonged fasting, the ability to digest food may be impaired or lost entirley because the stomach gradually stops secreting digestive juices.

 In answer to your question no you won't, but it would still be better if you could give yourself that snack.