No the “starvation mode” does not exist for any human being. Unfortunately even some well known health professionals have contributed to this myth but it is simply not true.
The so-called “starvation mode” is point where the body supposedly decide not to lose more weight, even when you eat “hardly anything”, by slowing down the metabolism because the body is afraid you will starve to death. To put your entire issue into perspective, first realize that the people around the world who truly die of starvation do not pass away overweight.
This myth was born from a combination of facts: 1) we physically move very little in the modern world, thus burn few daily calories compared to our ancestors, and 2) most people unconsciously or consciously tend to underreport their TRUE calorie intake by 20-45% (the more overweight, the more they underreport). Therefore we are actually eating more and moving less than we think.
The main reason the body comes to plateaus during dieting or exercise (besides consciously or unconsciously not properly following the plan), is that when weight is lost and you become more fit, your body uses fewer calories to perform the same workload. Your muscles are more efficient making work easier and you are moving less body weight during all activities, forcing you to add work or eat less in order to continue to progress. Also dieting often makes people become less energetic, forcing a reduction in their daily activities, therefore burning fewer calories overall. My general recommendation for plateaus for people who eat well and exercise regularly (therefore are “tapped out” as far as time or cutting calories) is to simply increase your daily movements at home or at the office. Stand or pace anytime you can instead of sitting: pace the room while on the phone or thinking, take stairs instead of elevators or escalators, park farther away from your final destination, take a walk at lunch, walk to a colleague’s office to talk rather than use e-mail or the intercom, etc. Additionally, you can try changing your workout, including the intensity and type of cardio you perform, which can help you burn a few more calories in the same workout timeframe. And never sit down or stop moving in the gym.