Are you looking at nutrients in the dietary intake or nutrient content from hair, skin, urine, blood and nails?

If the former then you should look for compliments of nutrients.  For example for bone health look for calcium, Vitamin K2, Vitamin D, magnesium and phosphorus.  All are necessary for healthy bone.  For immune system, skin, and bodily function look for water soluble vitamins B and C and vitamins A, E, and K1.  Then look at protein content and types of carbohydrates.  These should get you started.  Here are some newer books to look at:  Saunders Elsevier 'Biochemical, Physiological and Molecular Aspects of Human Nutrition' and Staci Nix · Elsevier Mosby  'William's Basic Nutrition and and Diet Therapy book'.

El principal indicador para mi concepto seria el consumo de energía, ya que por lo general nos da una idea del consumo y nos permite saber si existe normalidad en la aplicación de las encuestas ya que algunos datos pueden estar alterados o mal tomados, luego los análisis proximáles, y para mi parecer el consumo de lípidos, es importante,  también hay que considerar la fibra dietética y luego seria de acuerdo a lo que expone Julie observar los nutrientes de acuerdo a que esta enfocada la encuesta (que es lo que queremos evaluar en particular).

Saludos cordiales.

Is this for a population with under-nutrition? If so, iron and zinc are key markers. Also the B-vitamins are essential for a healthy diet for any population.

Joan indeed  this question needs to be answered with the given context in consideration. What kind of population set up and what are the related environmental and socioeconomic situations? When poor nutrition outcomes  are looked at through the lens of the UNICEF conceptual framework of malnutrition, not all causes of malnutrition are necessarily caused by inadequate dietary intake so it is important to consider the context. Even in more affluent circumstances it would be necessary  to collect information on other possible underlying and basic causes that can influence nutrition outcomes beyond diet quality.

Namukolo, you are correct in stating socioeconomic factors and environmental context is key in understanding under-nutrition or over-nutrition. Health beliefs are important factors and need to be considered. Certain foods may be plentiful but cultural beliefs may preclude their intake.

Dependiendo del tipo de población, en general lo que está dando problemas ya no es la escases de alimentos si no más bien su composición, por eso sería conveniente actualizar las tablas de compocisión de alimentos con nuevos criterios como la presencia de plomo, selenio y otros contaminantes. Por otro lado la composión lipídica esta dando problemas, sobre todo por su relación con enfermedades como diabetes y otras que están relacionadas con el sobrepeso, pero sobre todo con la acumulación de grasa no deseada en el organismo, bueno esa es la tendencia en mi País.

Saludos cordiales.

Juan, I believe for most population studies, those people with diabetes or diet-related diseases are not considered. The fact that certain areas have food contamination is an excellent point. This certainly would show in their blood and could cause dietary issues.

The first question to ask is a healthy diet for who? The answer to that would change according to the population you are dealing with. For young children the focus might be on iron, calcium, B12 or other nutrients contributing to growth. For adults you may want to follow fat distribution and sugar content. All that also would depend on the health status and any chronicle conditions. 

Estoy de acuerdo estimada Joan, pero un estudio nos puede dar elementos para alertar a la población de los excesos que podría suponer riesgo a largo plazo.

Thank you all for your answers! The study population consists of overweight adults so in this case the question is not about malnutrition.

The dietary data is collected by 48 hour diet recall and by "markers of healthy diet" I solely mean vitamins and minerals that would be meaningful to include in statistical analysis. I.e. the ones included should be good indicators of the diet quality and  somewhat reliably measurable with 48 hour recall.

With an overweight population, you can collect all parameters that have to be examined in bariatric surgery. With the loss of fat mass, you have to examine all liposoluble vitamines. We even saw deficiencies in vitamin K, by the way, also in dietary patients not only in patients of the surgery departement. The most important parameter here is definitely the vitamin D (25(OH)D3). Any way, you have to consider, that overweight patients do have a vitamin D deficiency in 90%, even before any intervention. Here an important parameter also is the parathormon.

The vitamin Bs (B12, B6, B1) are even more important in patients that underwent a surgery intervention of the stomach. There we collect the holotranscobalamin as active B12 fraction. The patients iron level, we messure with soluble transferrin receptor and the reticulocyte hemoglobin content.

Very interesting also would be the insuline, c-peptid and GLP-1 level, as markers for the pathway into the depots (liver, fat). This is a valuable source of information, if you also have the initial hormone levels.

How about measuring magnesium, potassium, zinc, vitamin B2, vitamin C, vitamin D, vitamin E, EPA and DHA? You don't say how many things you intend to measure.

There is a growing debate over the validity and value of data derived from memory-based dietary assessment methods (M-BMs) such as FFQs, food diaries, and dietary recalls (e.g., 24HRs). My empirically supported position is that all forms of M-BMs are pseudo-scientific, produce non-falsifiable and physiologically implausible data, and should not be used in nutrition research. Please see the recent 'Controversy & Debate' Series in the Journal of Clinical Epidemiology for details: Archer E, Marlow ML, Lavie CJ. The Fatal Flaws of Food Frequency Questionnaires and Other Memory-Based Dietary Assessment Methods. Journal of Clinical Epidemiology. 2018.

Link: Article Controversy and Debate: Memory based Methods Paper 1: The Fa...

Archer E, Marlow ML, Lavie CJ. Controversy and Debate: Memory-Based Dietary Assessment Methods Paper #3. Journal of Clinical Epidemiology. 2018. Link: Article Controversy and Debate: Memory-Based Dietary Assessment Meth...

اية Nutrients are divided into two major nutrients including carbohydrates, proteins, fats, and micronutrients including vitamins, minerals and water, all of which are essential to the body and which play an important role in protecting the body from diseases, especially malnutrition.

The foods we eat contain thousands of compounds and various chemicals. However, the number of chemicals of utmost importance in maintaining our health does not exceed a few dozen. These nutrients are what we must get from the foods we consume. Nutritionists classify nutrients into six major groups 1. Water 2 Carbohydrates 3. Fat 4. Proteins 5. Mineral salts. Vitamins 7. Other nutrients such as antioxidants

The healthy food system helps maintain and develop public health and is intended to improve the health of the individual. This system is based on supplying the body with essential nutrients such as fluids and "major nutrients", which the body needs in large quantities to survive and grow with. The "micronutrients" needed by the body in small quantities to promote growth, and improve, in addition to sufficient calories for the body. There are many innovative diets, the owners of which are diverse, but they are not based on science. These systems create confusion about what health food is, and give unnecessary false impressions about what can be unhealthy. These systems are fiercely promoted. For healthy people, a healthy diet is not as complex as some think; it contains mostly fruits and vegetables, while minimizing or preventing total processed foods and sweetened beverages. The requirements of this system can be obtained from several plant or animal sources, but those who follow A vegetarian diet that requires vitamin B-12 from an animal source. There are many guidelines published by medical and government food organizations to educate people about what they need to eat in order to be healthy. In addition, the labeling of food information on products is compulsory in several countries to allow the consumer to choose from the following: based on which of them has healthier ingredients. Healthy diet, along with healthy nutrition, involves daily exercise, and this method can reduce the risk of diseases such as obesity, heart disease, diabetes, hypertension and cancer.] There are dedicated diets called "therapeutic diets"; It is a system for people with different diseases and symptoms. There are ideas about these systems that existed before the current scientific development, as in traditional Chinese medicine. Other WHO recommendations include that the food chosen by the individual should have sufficient vitamin and mineral content and avoid direct toxicity such as Heavy metals, carcinogens and avoid foods contaminated with human pathogens, and the replacement of saturated fats, polyunsaturated fats in the diet, can reduce the risk of coronary heart disease, diabetes. Food guidelines for Americans provided by the United States Department of Agriculture recommend three types of diets, summarized in the table below, for a diet containing 2000 calories. These systems give importance to human health and environmental sustainability with a flexible approach. The great discovery of a sustainable diet is that the system rich in food from plant sources (such as vegetables, fruits, whole grains, legumes, nuts, and seeds), low in calories and food of animal origin, Healthier, and is also less harmful to the environment than the current American diet. This type of food can be achieved through many dietary patterns, as follows: Food groups - SubcategoryHealth style of the AmericasPeaceful vegetarian variety Mediterranean fruit2 (equivalent cup) 2 cups equivalent 2.5 cups Vegetables 2.5 cups equivalent 2.5 cups (Equivalent to 1.5 cups) equivalent weekly (1.5) cups equivalent weekly (red oranges) 5.5 cups equivalent weekly (5.5) cups equivalent weekly (5.5) cups weekly equivalent (Weekly cup) (5) weekly equivalent (5) cups weekly equivalent (legumes 1.5) cups equivalent weekly (3) k B) Equivalent weekly (1.5) cups weekly equivalent (other 4) weekly equivalent cup (4) weekly equivalent cup (4) cup equivalent weekly (cereals 6) equivalent ounce (6.5) ounce equivalent (6) Milk (3 oz equivalent) 3 oz equivalent (2 oz equivalent) protein food 3.5 oz equivalent (6.5) oz equivalent (meat) red and processed 12.5 (weekly equivalent) - 12. (weekly equivalent) poultry 10. 5 cups weekly equivalent (10 cups daily equivalent) 10 cups daily equivalent (3 cups) weekly (3 cups) weekly (3 cups) (Weekly) (4 cups weekly equivalent (processed soy)) tofu (0.5) cups equivalent weekly (8) cups equivalent weekly (0.5) cups equivalent weekly (oils 27 grams 27 grams 27 grams fat (Maximum) per gram (21) Maximum in grams (17) Maximum in grams (added sugar 30) Maximum in grams (36) Maximum in grams (29) Maximum in grams (American Heart Association, American Fund for Cancer Research, They recommend food that is mostly based on an untreated vegetable source, with a grain focus Whole, legumes, vegetables, and non-roasted fruits. This herbal food system contains a wide range of vegetables, and non-roasted fruits, which offer different colors such as red, green, yellow, purple, and orange. They noticed that the tomatoes cooked with oil and garlic, planted with cruciferous vegetables such as cauliflower, provide some protection against cancer, and this low-calorie health system, which can protect against the increase

I suggest a good diet involves these principles:

Eat savoury rather than sweet.

Eat vegetables rather than fruit.

Eat starch rather than sugar, as it breaks down to glucose not fructose.

Have variety.

Prepare your food at home from basic ingredients.

Have some salad.

Grains and pulses are better without the skins, because of the lectins in them.

Have plenty of omega three fats, and not much omega 6.

Eat butter not margarine.

Avoid hydrogenated oil.

Use saturated fats like coconut oil, goose fat or butter for frying and roasting, as unsaturated fats are badly damaged by heat.

Eat sourdough bread rather than fast produced bread, as the wheat is partially digested for you.

Eat hard cheese rather than milk, because of the sugar in milk called galactose, which is associated with artery disease.

Only have one course meals.

If you don't understand the label, don't eat the food.

If you are vegetarian. make sure you have enough omega three fat and zinc.

If you are vegan, make sure you have enough omega three fat, zinc, iron, calcium, vitamin D and vitamin B12.