Iron: Essential for healthy blood cells, iron becomes especially important when girls begin to menstruate. With each period, a woman loses small amounts of iron. “About 10% of American women are iron deficient,” says Dorothy Klimis-Zacas, PhD, a professor of nutrition at the University of Maine and co-editor of Nutritional Concerns of Women (CRC Press, 2003). “About 5% have iron deficiency anemia.” Symptoms of low iron include fatigue, impaired immunity, and poor performance at school or work.
Poor nutrition can manifest itself in many ways. The more obvious symptoms of a nutritional deficiency include dull, dry or shedding hair; red, dry, pale or dull eyes; spoon-shaped, brittle or ridged nails; bleeding gums; swollen, red, cracked lips; flaky skin that doesn't heal quickly; swelling in your legs and feet; wasted, weak muscles; memory loss; and fatigue.
As women, many of us are prone to neglecting our own dietary needs. You may feel you’re too busy to eat right, used to putting the needs of your family first, or trying to adhere to an extreme diet that leaves you short on vital nutrients and feeling cranky, hungry, and low on energy. Women’s specific needs are often neglected by dietary research, too. Studies tend to rely on male subjects whose hormone levels are more stable and predictable, thus sometimes making the results irrelevant or even misleading to women’s needs. All this can add up to serious shortfalls in your daily nutrition.
Among other things, you need calcium to build healthy bones and teeth, keep them strong as you age, regulate the heart’s rhythm, and ensure your nervous system functions properly. Calcium deficiency can lead to, or exacerbate, mood problems such as irritability, anxiety, depression, and sleep difficulties. If you don’t get enough calcium in your diet, your body will take calcium from your bones to ensure normal cell function, which can lead to weakened bones or osteoporosis. Women are at a greater risk than men of developing osteoporosis, so it’s important to get plenty of calcium, in combination with magnesium and vitamin D, to support your bone health.
However, 30% is still a lot of fat for one serving, so considered absolute values like how many grams of fat, carbohydrates, protein, etc. are consumed instead of relative values like "50% less fat." Additionally, reaching fitness goals is largely about calorie intake. More body fat and unwanted weight will be gained by eating 500 calories of a low-fat item than by eating 100 calories of a high-fat item, so keep this in mind.