I have lost 25 pounds this since January 1 this year by eating properly and working out. I am eating approximately 1200 calories per day, vegetables, nuts, chicken and fish. My blood pressure is 117/79 and my resting heart rate is 63-68 bpm. I have noticed sometimes when I go from a prone position to standing up that I get very dizzy and have to sit down to keep from falling. After I sit I can then stand and go on with my routine. Happened today at the health club, doing bench presses and went to stand up and almost fell down. Sat down, then stood up and was fine. Then did 30 minutes on elliptical trainer and kept heartrate above 115 the whole time. Is it just that I need to add more food to my diet?