DPG is pretty accurate in what he/she stated, though a bit generalized.
I know how the mentality of people today is, "lower cals = lower body weight". What also occurs however, is that your body attempts to conserve as much calories as it can by decreasing your metabolism because of the lack of calories you are giving it. Never forget how efficient our body is, it was meant to survive, not look good for the summer time.
Increasing the frequency of your meals will help increase your metabolism, which is why DPG stated 5-6 meals a day. Remember too, that it doesn't mean you stuff yourself in each of these meals, you will have to watch what you eat, but just enough to be satisfied for the next few hours before your next meal.
By the way, 120 and 130 are both considered average weight for one of your height.
How is your lifestyle as well? 18 years old, college life? Partying, studying, lack of sleep? To let you know, this is another thing we often don't know about. There are 3 ways in which we can expend energy.
1. Resting metabolic rate (while sleeping)
2. Physical Activity
3. Thermal effect of food (energy expended for processing of food and other internal body energy expenditure)
Which one of the three would you say probably uses up the most energy? I imagine most people would say Physical Activity, but no, you expend the most energy through your sleep (we are talking about average amount of sleep, not 30 minute naps and whatnot). So remember you need to sleep too.
