If all you have time for is a quick snack from the gas station or drugstore, know that you do have options, and if you know what you're looking for, it will be easier to find. When we asked registered dietitians to recommend snacks to buy at the drugstore, they tended to go for things like nuts and seeds that pack plenty of flavor (hi, wasabi chickpeas), plenty of protein, and not a whole lot else.
A vitamin is an organic compound required by an organism as a vital nutrient in limited amounts.[12] An organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. The term is conditional both on the circumstances and on the particular organism. For example, ascorbic acid (vitamin C) is a vitamin for anthropoid primates, humans, guinea pigs and bats, but not for other mammals. Vitamin D is not an essential nutrient for people who get sufficient exposure to ultraviolet light, either from the sun or an artificial source, as then they synthesize vitamin D in skin.[13] Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules, "vitamers", (e.g. vitamin E includes tocopherols and tocotrienols, vitamin K includes vitamin K1 and K2). The list: vitamins A, C, D, E, K, Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic Acid (B5), Vitamin B6, Biotin (B7), Folate (B9) and Vitamin B12. Vitamin intake below recommended amounts can result in signs and symptoms associated with vitamin deficiency. There is little evidence of benefit when consumed as a dietary supplement by those who are healthy and consuming a nutritionally adequate diet.[14]
Young adults. Teen girls and young women usually need more calories than when they were younger, to support their growing and developing bodies. After about age 25, a woman’s resting metabolism (the number of calories her body needs to sustain itself at rest) goes down. To maintain a healthy weight after age 25, women need to gradually reduce their calories and increase their physical activity.
Those who want to use natural healing methods, such as the use of food and supplements of essential nutrients to prevent or reverse illness, should consult therapists who are qualified to give advice on how natural therapies can help. I recommend that anyone interested in supplements read the references for this article as well as the archives of the Journal of Orthomolecular Medicine http://orthomolecular.org/library/jom/ and the Orthomolecular Medicine News Service http://orthomolecular.org/resources/omns/index.shtml . Both are free access online.
Sodium. Sodium is found in salt, but most of the sodium we eat does not come from salt that we add while cooking or at the table. Most of our sodium comes from breads and rolls, cold cuts, pizza, hot dogs, cheese, pasta dishes, and condiments (like ketchup and mustard). Limit your daily sodium to less than 2,300 milligrams (equal to a teaspoon), unless your doctor says something else. Check the Nutrition Facts label for sodium. Foods with 20% or more of the “Daily Value” of sodium are high in sodium.

A well-balanced diet, comprised of a variety of foods, adequately meets women’s needs for vitamins, minerals and energy. For good health, women need to pay special attention to calcium, iron and folate (folic acid) intake. A healthy diet also should minimize the intake of fat and sugar. Diets high in saturated or trans fat can promote high levels of blood cholesterol and increase risk for heart disease. A diet that includes high sugar provides empty calories, or calories that do not provide any nutritional value and often times replace more nutritious food selections.
Learn. Find out as much as you can about any dietary supplement you might take. Talk with your doctor, your pharmacist, or a registered dietitian. A supplement that seemed to help your neighbor might not work for you. If you are reading fact sheets or checking websites, be aware of the source of the information. Could the writer or group profit from the sale of a particular supplement? Read more about choosing reliable health information websites.

What you eat is even more important as you enter your 40s. Women need protein (meat, fish, dairy, beans, and nuts), carbohydrates (whole grains), fats (healthy oils), vitamins, minerals, and water. These foods have been linked to some disease prevention, such as osteoporosis, high blood pressure, heart disease, diabetes, and certain cancers. The American Academy of Family Physicians supports the development of healthy food supply chains in supplemental nutrition programs so as to broaden the availability of healthy food.
In 2015, the Australian Government's Department of Health published the results of a review of herbal supplements to determine if any were suitable for coverage by health insurance.[108] Establishing guidelines to assess safety and efficacy of botanical supplement products, the European Medicines Agency provided criteria for evaluating and grading the quality of clinical research in preparing monographs about herbal supplements.[109] In the United States, the National Center for Complementary and Integrative Health of the National Institutes of Health provides fact sheets evaluating the safety, potential effectiveness and side effects of many botanical products.[110]
The United States Food and Drug Administration, Office of Inspections, Compliance, Enforcement, and Criminal Investigations, monitors supplement products for accuracy in advertising and labeling, and when finding violations, warns manufacturers of impending enforcement action, including search and seizure, injunction, and/or financial penalties, such as for a Maine supplement company in 2017.[80] The United States Federal Trade Commission, which litigates against deceptive advertising,[67] established a consumer center to assist reports of false health claims in product advertising for dietary supplements,[81] and, in 2017, successfully sued nine manufacturers for deceptive advertising of dietary supplements.[82]
And, once I have my burger or pizza or margarita or whatever, I go back to my normal healthy eating.  And this works well for me. The funny thing is I usually don’t even enjoy the cheat days as much as I think I will because I find the foods too salty or too sweet or too greasy.  I actually can’t wait to get back onto my normal, healthy foods as soon as possible.
Animal products, such as meat, fish and poultry are good and important sources of iron. Iron from plant sources are found in peas and beans, spinach and other green leafy vegetables, potatoes, and whole-grain and iron-fortified cereal products. The addition of even relatively small amounts of meat or foods containing vitamin C substantially increases the total amount of iron absorbed from the entire meal.
Compared to pharmaceutical drugs, supplements of most essential nutrients are quite harmless. However, some supplements may have poor quality, or contain toxic metals such as lead or cadmium. Therefore, it is the duty of our authorities to ensure that potentially hazardous products or supplements of poor quality are not sold, and that consumers are offered fair prices in a free market. An example where the Norwegian authorities do not follow up such basic duties is that pharmacies demand more than 1,600 Norwegian Kroner (about $190) per kg of vitamin C in powder form, which would cost less than $20 with free competition and no restrictions in permitted doses or outlets.
The VITAL trial showed that neither vitamin D nor fish oil supplementation significantly reduced the incidence of cardiovascular disease (CVD). Conversely, current evidence supports the benefits of multiple dietary patterns, especially the Mediterranean diet, in primary prevention of CVD. Health effects of low-carbohydrate diets depend on the food sources of macronutrients.
For instance, foods rich in vitamin E and beta-carotene are healthy and can help reduce cancer risk. However, the U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians (AAFP) recommend against taking vitamin E or beta-carotene for the prevention of cardiovascular disease. People who smoke or are at risk for lung cancer also should avoid beta-carotene. It can increase their risk of lung cancer.
Protein-containing supplements, either ready-to-drink or as powders to be mixed into water, are marketed as aids to people recovering from illness or injury, those hoping to thwart the sarcopenia of old age,[20][21] to athletes who believe that strenuous physical activity increases protein requirements,[22] to people hoping to lose weight while minimizing muscle loss, i.e., conducting a protein-sparing modified fast,[23] and to people who want to increase muscle size for performance and appearance. Whey protein is a popular ingredient,[21][24][25] but products may also incorporate casein, soy, pea, hemp or rice protein.

It's even more important for older people to stay hydrated. Age can bring a decreased sensitivity to thirst. Moreover, it's sometime harder for those who are feeble to get up and get something to drink. Or sometimes a problem with incontinence creates a hesitancy to drink enough. Those who are aging should make drinking water throughout the day a priority.

Eat a balance of carbohydrates, proteins and fats at each meal and choose foods rich in fiber, vitamins and minerals. A good way to do this is to fill your plate with 3–4 food groups at each meal. Eat a combination of protein-rich foods, whole grains, dairy, fruits and vegetables, and incorporate the groups you miss into other meals and snacks throughout the day. Stick to healthy portions — see our Essential Guide to Portion Sizes for tips.
For example, while increased consumption of fruits and vegetables are related to decreases in mortality, cardiovascular diseases and cancers, supplementation with key factors found in fruits and vegetable, like antioxidants, vitamins, or minerals, do not help and some have been found to be harmful in some cases.[86][87] In general as of 2016, robust clinical data is lacking, that shows that any kind of dietary supplementation does more good than harm for people who are healthy and eating a reasonable diet but there is clear data showing that dietary pattern and lifestyle choices are associated with health outcomes.[88][89]