I'm 18 years old, female, 5'9 and 131 pounds. I go on brisk walks every day as well as going to the gym later on in the day most days for weight lifting and sometimes more cardio. I consider myself lightly active. For the past two months I've been trying to maintain weight after purposefully gaining 7 pounds. I was a bit too thin for awhile and did not have my period so I put on some weight and got a period last month and am hoping to see it again this month although I haven't yet. Anyway, I've noticed I don't seem to gain weight on a weekly average calorie intake of around 1800-2000 calories. But, some calculators I've used say I need only a little over 1600 calories even though I exercise with regularity. I was eating just under 1500 calories when I was in the 120's and losing weight still. Should I stick with the 1800-2000 calories? 1600 calories is quite a small amount of food for a maintainer IMO...it's hard for me to stick to that. I'm just worried about gaining more weight. I'd very much like to stay where I am. What do you all think?