A long term calorie deficit can mess with your blood sugar levels, reduce bone mass, cause weakness, fatigue, cold intolerance, irregular menstrual periods, dizziness, constipation and swelling of the hands and feet (source). If a woman decides to get thin by maintaining a steep calorie deficit (1200 calories is very steep) and pairs it with long sessions of steady-state cardio, it results it thyroid issues. “Too little T3 (hypothyroidism), and the body accumulates body fat with ease, almost regardless of physical activity level. Women inadvertently put themselves into a hypothyroid condition when they perform so much steady-state cardio” (source).Women: If you are trying to go about your business during the day, on only 1200 calories, and perform cardio to burn those dreaded calories, you really are not going to succeed. You will most likely pass out.
via 1200 Calories.