Everyone seems to have food allergies these days, but in fact, such allergies are rare. According to the National Institute of Allergy and Infectious Diseases, while one in three adults think they have a food allergy or modify their family's diet, only about four percent do. A food allergy is an abnormal immune-system response to certain foods (most commonly, fish, shellfish, peanuts, other nuts and eggs). Symptoms can include hives, rashes, nasal congestion, nausea, diarrhea and gas. However, symptoms of food intolerance—such as intestinal distress—may mimic those of a food allergy. You may want to talk to an allergist about diagnosis and treatment. Whether you have food allergies or intolerance, you will need to develop a diet that fits your needs and avoids foods that trigger a reaction.
Obviously, the best treatment plan for poor nutrition is to change your diet. Most Americans eat too little of what they need and too much of that they don't. For many women, decreasing fat and sugar consumption and increasing fruit, vegetables and grains in your diet can make a big difference. Many women also need to boost consumption of foods containing fiber, calcium and folic acid. Compare your diet to that suggested by the food pyramid and compare your nutrient intake to the suggested daily levels. Adjust accordingly, and you may be able to dramatically improve your health.
A recent study predicts that global warming may reduce the nutrient density in many foods worldwide.  Atmospheric CO2 is estimated to surpass 550 ppm in the next 30-80 years, leading to larger crops with lower content of protein, iron and zinc per energy unit. Assuming that diets remain constant, while excluding other climate impacts on food production, the researchers estimated that elevated CO2 could cause an additional 175 million people to be zinc deficient and an additional 122 million people to be protein deficient in 2050. Anemia would increase significantly if crops lose even a small amount of iron. The highest risk regions - South and Southeast Asia, Africa, and the Middle East - are especially vulnerable, since they do not have the means and access to compensate using nutritional supplements.
You've heard to make breakfast the biggest meal of your day, but you may not be that hungry when you wake up. In fact, "your biggest meal should be around noon when your digestion is at its peak and you can feed your body when it actually needs fuel," says Dr. Lipman. That means you don't need a huge meal at dinner only to sit and catch up on True Detective and then go to bed. But "big" doesn't mean burger and fry big. At lunch, emphasize protein and greens, like a hearty bowl of lentil soup and kale salad. Another bonus: after dinner you won't have the feeling you need to unbutton your pants.
Retinol (Vitamin A) B vitamins: Thiamine (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Pyridoxine (B6) Biotin (B7) Folic acid (B9) Cyanocobalamin (B12) Ascorbic acid (Vitamin C) Ergocalciferol and Cholecalciferol (Vitamin D) Tocopherol (Vitamin E) Naphthoquinone (Vitamin K) Calcium Choline Chromium Cobalt Copper Fluorine Iodine Iron Magnesium Manganese Molybdenum Phosphorus Potassium Selenium Sodium Sulfur Zinc
Make half your plate fruits and vegetables: Choose red, orange, and dark-green vegetables like tomatoes, sweet potatoes, and broccoli, along with other vegetables for your meals. Add fruit to meals as part of main or side dishes or as dessert. The more colorful you make your plate, the more likely you are to get the vitamins, minerals, and fiber your body needs to be healthy.
Overall diet is an important first consideration for those considering nutritional supplementation. Healthy dietary habits can help optimize nutrition and the absorption of supplements, and nutritional supplements cannot substitute for a diet that is not nutritionally balanced in the first place. Supplements are best used moderately to supply any extra nutritional requirements. Sound diets contain a variety of wholesome foods. At least five servings per day of fruits and vegetables are recommended, as well as the inclusion of whole grains in the diet. Variety in the diet is important to provide a full range of vitamins and minerals. Overeating inhibits digestion and absorption of nutrients, while regular exercise contributes to sound nutrition, by improving metabolism and digestion. Drinking plenty of clean water prevents dehydration, improves digestion, and helps the body flush out impurities.
As continual research on the properties of supplements accumulates, databases or fact sheets for various supplements are updated regularly, including the Dietary Supplement Label Database, Dietary Supplement Ingredient Database, and Dietary Supplement Facts Sheets of the United States. In Canada where a license is issued when a supplement product has been proven by the manufacturer and government to be safe, effective and of sufficient quality for its recommended use, an eight-digit Natural Product Number is assigned and recorded in a Licensed Natural Health Products Database. The European Food Safety Authority maintains a compendium of botanical ingredients used in manufacturing of dietary supplements.
Ditching the habit and instead focus on good-for-you foods, says Frank Lipman, MD, integrative and functional medicine physician, founder of Eleven Eleven Wellness Center and author of The New Health Rules. Instead of how many calories, ask yourself where the food came from and if it's nutritious. "Healthy, nutrient-rich foods will keep hunger at bay, help maintain stable blood sugar levels, minimize cravings, and help your brain signal your belly when you're full," he says. In other words, you don't have to go through all the trouble of counting.
There are thousands of dietary supplements on the market, including 40+ essential nutrients alone and in various combinations, i.e. vitamins, minerals, trace elements and fatty acids. However, a number of other nutrients are "conditionally essential", meaning that the body normally can make these molecules, but some people do not make optimal amounts. Examples are L-carnitine, alpha-lipoic acid, the methyl donor betaine,  chondroitin sulfate, coenzyme Q10, choline, amino acids such as tyrosine or arginine, and "essential" sugars normally formed in the body. 
Think smaller portions. Serving sizes have ballooned recently. When dining out, choose a starter instead of an entree, split a dish with a friend, and don’t order supersized anything. At home, visual cues can help with portion sizes. Your serving of meat, fish, or chicken should be the size of a deck of cards and half a cup of mashed potato, rice, or pasta is about the size of a traditional light bulb. By serving your meals on smaller plates or in bowls, you can trick your brain into thinking it’s a larger portion. If you don’t feel satisfied at the end of a meal, add more leafy greens or round off the meal with fruit.
2. Eat a variety of foods. As we covered earlier, the brain craves novelty. While you may not be able to replicate the crunchy/creamy contrast of an Oreo, you can vary your diet enough to keep things interesting. For example, you could dip a carrot (crunchy) in some hummus (creamy) and get a novel sensation. Similarly, finding ways to add new spices and flavors to your dishes can make eating healthy foods a more desirable experience.
Carbohydrates should provide 45%–65% of your daily calories. Most of those calories should come from the complex carbohydrates in high-fiber and unrefined foods, such as bran cereal and other whole-grain products, brown rice, beans and other legumes, and many fruits and vegetables. These carbohydrates are digested and absorbed slowly, so they raise the blood sugar gradually and don't trigger a large release of insulin. People who eat lots of these foods have higher HDL ("good") cholesterol levels and a lower risk of obesity, diabetes, and heart disease. A good amount of soluble fiber in the diet lowers LDL ("bad") cholesterol, and high-fiber diets reduce the risk of intestinal disorders ranging from constipation and diverticulosis to hemorrhoids. Some studies have shown that fiber may help reduce the risk of colon cancer. Men need more fiber than women: 38 vs. 25 grams a day before the age of 50 and 30 vs. 21 grams a day thereafter.