Eat healthy fats. According to the American Heart Association, women should get at least five to 10 percent of total daily calories from omega-6 fatty acids (equal to 12 to 20 grams), and between 0.5 and 3 grams of omega-3 fatty acids, depending on individual risk for heart disease. Good sources of omega-6 fatty acids include sunflower, safflower, corn, cottonseed and soybean oils. And good sources of omega-3 fatty acids include fatty fish, tofu and other forms of soybeans, canola, walnuts, flaxseed, and their oils. Talk with your health care professional about how much of these beneficial oils you should be getting, how you can best incorporate them into your diet and whether or not you should be taking them in supplement form.
Say no to sugary drinks. The average American drinks around 45 gallons of soda each year, according to the Beverage Marketing Corporation. Other than the obvious risk of Type 2 diabetes and obesity, consuming sugary beverages can also cause liver damage, premature aging and anxiety. So, instead of sipping packaged juice or soda, go for unsweetened beverages or infused water.
Part of the reason why so many women fail to get the amount of iron they need is because one of the best sources of iron is red meat (especially liver) which also contains high levels of saturated fat. While leafy green vegetables and beans are also good sources of iron—and don’t contain high levels saturated fat—the iron from plant foods is different to the iron from animal sources, and not absorbed as well by the body. Other foods rich in iron include poultry, seafood, dried fruit such as raisins and apricots, and iron-fortified cereals, breads, and pastas.
Higher dosages may be given after having consulted a therapist who has measured the ratio of omega-6 to omega-3 fatty acids in relevant cell membranes (red blood cells). In most industrialized countries, many people get too much of the omega-6 fatty acids, and would therefore benefit from eating more seafood or taking supplements with omega-3 fatty acids derived from organisms low in the food chain (algae, krill). Flax seeds contain a high level of the essential omega-3 fatty acid alpha-linolenic acid, and freshly ground flaxseed meal or flax oil can be mixed with breakfast cereals or smoothies. Note that it may be advisable to limit eating farmed fish to once per week, since their fodder contains less omega-3 fatty acids than the food eaten by wild fish, and possibly also contains more contaminants.  Some researchers even warn against letting children eat too much fish because of the content of environmental toxins. [13,14]
^ Jump up to: a b c Schwingshackl, L; Boeing, H; Stelmach-Mardas, M; Gottschald, M; Dietrich, S; Hoffmann, G; Chaimani, A (2017). "Dietary Supplements and Risk of Cause-Specific Death, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis of Primary Prevention Trials". Advances in Nutrition: An International Review Journal. 8 (1): 27–39. doi:10.3945/an.116.013516. PMC 5227980. PMID 28096125.
Omega-3 fatty acids are essential for the neurological and early visual development of your baby and for making breast milk after birth. Aim for two weekly servings of cold water fish such as salmon, tuna, sardines, herring, or anchovies. Sardines are widely considered the safest and most sustainable fish to eat, while seaweed is a rich vegetarian source of Omega-3s.
Studies link high sodium intake to higher blood pressure, and evidence suggests that many people at risk for high blood pressure can reduce their risk by consuming less salt or sodium, as well as following a healthy diet. Most Americans consume more sodium than they need. The recommended amount is less than 2,300 mg per day for children and adults to age 50. The limit drops to 1,500 mg per day for those 51 and older or those of any age who are African American or have hypertension, diabetes or chronic kidney disease. You get 2,300 mg in just one teaspoon of salt. One good way to reduce your sodium intake is to eat fewer prepared and packaged foods.
A spokesperson for optimal nutritional intake is the well-known biochemist Bruce Ames, who proposed the "triage theory of nutrients," in which enzymes responsible for cell maintenance functions evolved to have lower affinity for the essential vitamin and mineral cofactors than the enzymes responsible for short-term survival, to preserve life during times of famine. 
Now, the benefits of good nutrition are fairly obvious to most of us. You have more energy, your health improves, and your productivity blossoms. Healthy eating also plays a huge role in maintaining a healthy weight, which means a decreased risk of type 2 diabetes, certain cancers, heart problems, high blood pressure, and a host of other health ailments. (Genetics also plays a significant role. I'm not some crazy person who thinks genes don't matter.)
Some supplements that were found to have health benefits in observational studies turned out, with more rigorous testing, to be not only ineffective but also risky. Vitamin E, which was initially thought to protect the heart, was later discovered to increase the risk for bleeding strokes. Folic acid and other B vitamins were once believed to prevent heart disease and strokes—until later studies not only didn't confirm that benefit but actually raised concerns that high doses of these nutrients might increase cancer risk.
Use MyPlate (PDF – 281 KB) as a guide to build a healthy diet. Think about filling your plate with foods from the five food groups — fruits, vegetables, grains, proteins, and dairy — at each meal. Snacks can be a good way to fill in fruits and whole grains you might have missed at meals. Most of us don’t need complicated calorie counting programs or special recipes for healthy eating.
People use dietary supplements for a wide assortment of reasons. Some seek to compensate for diets, medical conditions, or eating habits that limit the intake of essential vitamins and nutrients. Other people look to them to boost energy or to get a good night's sleep. Postmenopausal women consider using them to counter a sudden drop in estrogen levels.
Dietary supplements are complex products. The FDA has established good manufacturing practices (GMPs) for dietary supplements to help ensure their identity, purity, strength, and composition. These GMPs are designed to prevent the inclusion of the wrong ingredient, the addition of too much or too little of an ingredient, the possibility of contamination, and the improper packaging and labeling of a product. The FDA periodically inspects facilities that manufacture dietary supplements.