Nutritional intakes and nutrients

Nutritional intakes and nutrients

Nutritional intakes and nutrients

What is a nutrient?

Nutrients are all the food substances that the body absorbs and uses to function. Food becomes nutrients under the action of digestive juices. Thanks to research that began in the early twentiethe century, we are now able to identify the main nutrients, measure them and specify their action in maintaining health and preventing certain diseases. It should be noted, however, that the total amount of food chemicals is practically incalculable – an apple contains more than 250! In addition, this chemistry is constantly changing, depending on whether the food is more or less fresh, cooked, grilled, fermented, etc.

 

Traditionally, nutrients are classified into three groups:

  • Macronutrients : proteins, carbohydrates, lipids and alcohols. They constitute the bulk of food. Proteins are the basic material that makes up the physical structure of the body, while carbohydrates and fats are mostly energetic in nature: fuel.
  • Micronutrients : present in very small amounts in food, they do not provide energy, but are necessary for the functioning of cells. They include over a hundred vitamins and minerals. These are divided into major minerals (daily intake of the order of one gram: sodium, potassium, calcium, phosphorus, magnesium, etc.) and trace elements or trace elements (intake of less than a hundred micrograms).
  • Fibers Strictly speaking, they are not nutrients because the body does not absorb them, but they play a fundamental role in digestion functions and, hence, in general health.

For more details, see our sheet Nutrient chemistry.

 

It is now possible to establish the role of many nutrients from knowledge of nutrition as well as biochemistry, medicine, epidemiology, food toxicology and food safety. Some trace elements are absolutely vital, others just desirable or beneficial. It has also been estimated how much they are needed for energy needs and maintenance of body structure, by gender and different age groups.

Note that, taken in very large quantities, several nutrients can also have a therapeutic role. This is the case, for example, with vitamin B3 which, in very high doses, treats hypercholesterolemia.

 

Big and small nutrients

Depending on the volume of the nutrient, its content in a food is expressed in grams (g), milligrams (mg – thousandth of a g) or micrograms (µg – millionth of a g). An orange, for example, contains 70 mg vitamin C and 26 µg of vitamin B9.

Most, if not all of the nutrients essential for health would be listed and evaluated by public health agencies, except perhaps for a few trace minerals. “There are, of course, many other nutrients for which no recommendation has been issued, but we do not yet have enough data on them, indicates nutritionist Mireille Dubost.1. On the other hand, there has been a lot of talk for some time about the many phytochemicals (lycopene from tomato or carotene from carrot, for example) that are found in foods of plant origin. At the moment, they are not considered essential, despite the health benefits they bring, but that could change. The nutrient issue is changing rapidly. “

Official nutritional intakes

Several countries have established standards for essential nutrients. They may vary from country to country depending on various factors such as climate and dietary and cultural habits.

For the member countries of the European Community, taking into account the need for harmonization, standards were established which resulted in the creation of Recommended Daily Allowances (RDI)2. However, France has its own standards which translate into Recommended Nutritional Intakes (ANC)3.

In recent years, Canada and the United States have granted their standards, established by experts from the National Academy of Sciences (US)4, a private, not-for-profit corporation. They are grouped together under the name of Nutritional Reference Intakes (DRIs).

 

The various DRIs5

The term “Dietary Reference Intakes” (DRIs) designates four types of reference values:

Estimated average requirement (EAR). Amount of a nutrient deemed necessary to meet the needs of the average healthy population (i.e. 50% of that population). BMEs have been established for different age groups of both sexes from clinical studies. At the moment, 19 nutrients have a BME standard.

Recommended nutritional allowance (RDA). Calculated from the EARs, the ANRs are established to meet the needs of the majority (97,5%) of the healthy population. They are therefore higher than the BMEs.

Sufficient intake (AS). If we do not yet have sufficient data to establish the BME and ANR, we refer to an estimate (approximate figures) of the quantity consumed by a group of healthy people.

Maximum tolerable intake (AMT). Maximum amount of a nutrient that the majority of the population can ingest continuously without risking adverse health effects.

 

A set of DRIs is established for each nutrient for which sufficient information is available. For each nutrient, there is an Estimated Average Requirement (EAR) and a Recommended Dietary Allowance (RDA) or Adequate Intake (SA). An SA is established for a nutrient when there is insufficient data to determine a BME and ANR. In addition, maximum tolerable intakes (MLIs) have been set for many nutrients. All of the DRI data is grouped into three tables that can be found on the Health Canada site6-8 .

 

For a list of nutrients that are subject to standards, click here.

 

“For most people,” explains nutritionist Mireille Dubost, “needs are between estimated average needs (EAR) and recommended nutritional intake (ANR). The best, then, is to guide yourself with these, without exceeding the maximum tolerable intakes (AMT), which ensures an excellent diet and an almost zero risk of suffering from deficiencies in essential nutrients. “

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