Do you often feel tired, short of breath or do your friends say you look unusually pale? If so, you may be suffering from iron deficiency anemia, the most common nutritional disorder on the plane. More than 30 percent of the world's population is anemic, according to the World Health Organization. This is a condition in which the body lacks the iron mineral in red blood cells, which means that less oxygen reaches the cells. You should consult your doctor if you feel: - Extreme fatigue and lack of energy - Shortness of breath - Noticeable heartbeat (heart palpitations) - Pale skin One of the main reasons for anemia is the lack of iron in our diet. Foods that contain iron include: -Red meat -Liver -Eggs -Fish Also dark green leafy vegetables, such as kale and spinach, and legumes, such as peas and lentils.