Understanding Daily Reference Intakes

Dietary Reference Intakes (DRI) are the recommendation levels for specific nutrients and consist of a number of different types of recommendations. This DRI system is used in both the United States and Canada.

Daily Reference Intakes: A Brief Overview

“Dietary Reference Intakes” (DRI) is an umbrella term for four reference values:

• estimated average requirements (EAR)
• recommended dietary allowances (RDA)
• adequate intakes (AI)
• tolerable upper intake levels (UL)

The DRIs are not minimum or maximum nutritional requirements and are not intended to fit everybody. They are to be used as guides only for the majority of the healthy population.^[1]
DRIs are important not only to help the average person determine whether their intake of a particular nutrient is adequate, they are also used by health-care professionals and policy makers to determine nutritional recommendations for special groups of people who may need help reaching nutritional goals. This includes people who are participating in programs such as the Special Supplemental Food Program for Women, Infants, and Children. The DRI is not appropriate for people who are ill or malnourished, even if they were healthy previously.

Determining Dietary Reference Intakes

Each DRI value is derived in a different way. See below for an explanation of how each is determined.

Estimated Average Requirements.

The EAR for a nutrient is determined by a committee of nutrition experts who review the scientific literature to determine a value that meets the requirements of 50 percent of people in their target group within a given life stage and for a particular sex. The requirements of half of the group will fall below the EAR and the other half will be above it. It is important to note that, for each nutrient, a specific bodily function is chosen as the criterion on which to base the EAR. For example, the EAR for calcium is set using a criterion of maximizing bone health. Thus, the EAR for calcium is set at a point that will meet the needs, with respect to bone health, of half of the population. EAR values become the scientific foundation upon which RDA values are set.

Recommended Daily Allowances.

Once the EAR of a nutrient has been established, the RDA can be mathematically determined. While the EAR is set at a point that meets the needs of half the population, RDA values are set to meet the needs of the vast majority (97 to 98 percent) of the target healthy population. It is important to note that RDAs are not the same thing as individual nutritional requirements. The actual nutrient needs of a given individual will be different than the RDA. However, since we know that 97 to 98 percent of the population’s needs are met by the RDA, we can assume that if a person is consuming the RDA of a given nutrient, they are most likely meeting their nutritional need for that nutrient. The important thing to remember is that the RDA is meant as a recommendation and meeting the RDA means it is very likely that you are meeting your actual requirement for that nutrient.

Understanding the Difference

There is a distinct difference between a requirement and a recommendation. For instance, the DRI for vitamin D is a recommended 600 international units each day. However, in order to find out your true personal requirements for vitamin D, a blood test is necessary. The blood test will provide an accurate reading from which a medical professional can gauge your required daily vitamin D amounts. This may be considerably more or less than the DRI, depending on what your level actually is.

Adequate intakes (AIs) are created for nutrients when there is insufficient consistent scientific evidence to set an EAR for the entire population. As with RDAs, AIs can be used as nutrient-intake goals for a given nutrient. For example, there has not been sufficient scientific research into the particular nutritional requirements for infants. Consequently, all of the DRI values for infants are AIs derived from nutrient values in human breast milk. For older babies and children, AI values are derived from human milk coupled with data on adults. The AI is meant for a healthy target group and is not meant to be sufficient for certain at-risk groups, such as premature infants.

The concept of a tolerable upper intake level (UL) was established to help distinguish healthful and harmful nutrient intakes. Developed in part as a response to the growing usage of dietary supplements, ULs indicate the highest level of continuous intake of a particular nutrient that may be taken without causing health problems. When a nutrient does not have any known issue if taken in excessive doses, it is not assigned a UL. However, even when a nutrient does not have a UL it is not necessarily safe to consume in large amounts.

Figure 1.2.1.1 Dietary Reference Intakes Graph.

This graph illustrates the risks of nutrient inadequacy and nutrient excess as we move from a low intake of a nutrient to a high intake. Starting on the left side of the graph, you can see that when you have a very low intake of a nutrient, your risk of nutrient deficiency is high. As your nutrient intake increases, the chances that you will be deficient in that nutrient decrease. The point at which 50 percent of the population meets their nutrient need is the EAR, and the point at which 97 to 98 percent of the population meets their needs is the RDA. The UL is the highest level at which you can consume a nutrient without it being too much—as nutrient intake increases beyond the UL, the risk of health problems resulting from that nutrient increases.

The Acceptable Macronutrient Distribution Range (AMDR) is the calculated range of how much energy from carbohydrates, fats, and protein is recommended for a healthy diet adequate of the essential nutrients and is associated with a reduced risk of chronic disease. The ranges listed in Table 1.2.1.1 “Acceptable Macronutrient Distribution Ranges (AMDR) For Various Age Groups” allows individuals to personalize their diets taking into consideration that different subgroups in a population often require different requirements. The DRI committee recommends using the midpoint of the AMDRs as an approach to focus on moderation. ^[2]

Nutrient needs vary throughout development. Carbohydrates are required the most, followed by fat, then protein.

Discovering Nutrition Facts

The Labels on Your Food

Understanding the significance of dietary guidelines and recommendations in planning your nutrient intakes can make you better equipped to select the right foods the next time you go to the supermarket.

In the United States, the Nutrition Labeling and Education Act passed in 1990 and came into effect in 1994. In Canada, mandatory labeling came into effect in 2005. As a result, all packaged foods sold in the United States and Canada must have nutrition labels that accurately reflect the contents of the food products. There are several mandated nutrients and some optional ones that manufacturers or packagers include.

In, 2017 a new Nutrition Facts label for packaged foods was announced. This label reflects new scientific information and will make it easier for consumers to make informed food choices. Some of the changes made to the label include the following:^[3]

• The serving size has been made more
  • consistent, so that it’s easier to compare similar foods, and
  • realistic, so that it reflects the amount that Canadians typically eat in one sitting.
• The information on serving size and calories has been made easier to find and read by
  • increasing the font size of serving size and calories and
  • adding a bold line under the calories.
• The % daily values have been revised based on updated science.
• A new % daily value for total sugars has been added.
• The list of nutrients has been updated to
  • include potassium, because
    • it’s important for maintaining healthy blood pressure, and
    • most Canadians are not getting enough of this nutrient, and
  • remove vitamin A and vitamin C, because most Canadians get enough of these nutrients in their diets.
• The amounts in milligrams (mg) for potassium, calcium and iron have been added.
• A footnote has been added at the bottom of the table about % daily value to help consumers understand
  • how much sugar and other nutrients (like sodium) are in their food, and that
  • 5% or less is a little, and
  • 15% or more is a lot.

Figure 1.2.1.2 Nutrition facts table changes

Reading the Label

The first part of the Nutrition Facts panel gives you information on the serving size and how many servings are in the container. For example, a label on a box of crackers might tell you that twenty crackers equals one serving and that the whole box contains 10 servings. All other values listed thereafter, from the calories to the dietary fiber, are based on this one serving. On the panel, the serving size is followed by the number of calories and then a list of selected nutrients. You will also see “Percent Daily Value” on the far right-hand side. This helps you determine if the food is a good source of a particular nutrient or not. The Daily Value (DV) represents the recommended amount of a given nutrient based on the RDI of that nutrient in a 2,000-kilocalorie diet. The percentage of Daily Value (percent DV) represents the proportion of the total daily recommended amount that you will get from one serving of the food. For example, in the older food label in Figure 1.2.1.3 “Reading the Older Nutrition Label,” the percent DV of calcium for one serving of macaroni-and-cheese is 20 percent, which means that one serving of macaroni and cheese provides 20 percent of the daily recommended calcium intake. Since the DV for calcium is 1,000 milligrams, the food producer determined the percent DV for calcium by taking the calcium content in milligrams in each serving, and dividing it by 1,000 milligrams, and then multiplying it by 100 to get it into percentage format. Whether you consume 2,000 calories per day or not you can still use the percent DV as a target reference.

Generally, a percent DV of 5 is considered low and a percent DV of 15 is considered high. This means, as a general rule, for fat, saturated fat, trans fat, cholesterol, or sodium, look for foods with a low percent DV. Alternatively, when concentrating on essential mineral or vitamin intake, look for a high percent DV. To figure out your fat allowance remaining for the day after consuming one serving of macaroni-and-cheese, look at the percent DV for fat, which is 18 percent, and subtract it from 100 percent. To know this amount in grams of fat, read the footnote of the food label to find that the recommended maximum amount of fat grams to consume per day for a 2,000 kilocalories per day diet is 65 grams. Eighteen percent of sixty-five equals about 12 grams. This means that 53 grams of fat are remaining in your fat allowance. Remember, to have a healthy diet the recommendation is to eat less than this amount of fat grams per day, especially if you want to lose weight.

Figure 1.2.1.3 Reading the Older Nutrition Label.

Of course, this is a lot of information to put on a label and some products are too small to accommodate it all. In the case of small packages, such as small containers of yogurt, candy, or fruit bars, permission has been granted to use an abbreviated version of the Nutrition Facts panel. To learn additional details about all of the information contained within the Nutrition Facts panel, see the following website: https://www.canada.ca/en/health-canada/services/food-labelling-changes.html#a1

List of Ingredients

The updated guidelines for food labels also include changes to how ingredients are listed. These changes make it easier to find, read and understand the list of ingredients. Changes include the following:^[4]:

• grouping sugars-based ingredients in brackets after the name ‘sugars’
  • this will help consumers identify all of the sources of sugars added to a food
• listing food colours by their individual common names
• making the text in black font on white or neutral background
• creating minimum type height requirements for ingredients
• using bullets or commas to separate ingredients
• using both upper and lower case letters for the ingredients in the list
• the same format rules will apply to any ‘contains’ statement indicating the presence or potential presence of
  • priority food allergens,
  • gluten sources, or
  • added sulphites

Figure 1.2.1.4 List of Ingredients 

Serving Size

Changes have been made to how serving sizes are presented to better represent the amount that Canadians eat in one sitting. Serving sizing will also now be more consistent between products making it easier to compare between similar foods and know how many calories and nutrients are being consumed. The changes are different for single serving and multi-serving packages. 

Foods in Single Serving Containers

On a single serving container that contains up to 200% of the previous serving amount for that food, the serving size will be the amount in the whole container. For example, the nutrition facts for a 473mL carton of milk would previously be in reference to 250mL of milk however 250mL is less than 200% of 473mL therefore the nutrition label is based on the contents of the entire container. If the container was above 500mL (200% of 250mL) the serving size would not have to be based on the entire container. 

Figure 1.2.1.5 Foods in Single Serving Containers 

Foods in Multi-Serve Packages

In multi-serve packages serving sizes will be based on an amount that is close to what would be typically consumed. Serving sizes are based on how a food can be categorized. The categories are the following:

• foods that can be measured
• foods that come in pieces or are divided 
• amounts of foods that are typically eaten 

These factors allow serving sizes between similar foods to be more consistent so consumers can more easily compare. 

Foods That Can Be Measured

Foods that can be measured, like yogurt, will be shown as a common household measurement such as 

• a cup,
• a teaspoon, or
• a tablespoon.

This will additionally be paired with its metric equivalent in millilitres or grams. Similar products will be required to have the same millilitres or gram amount to allow for easier comparison. 

For example in Figure 1.2.1.6 “Foods That Can Be Measured”, the reference amount for yogurt is 175g. This is the typical amount of yogurt eaten in one sitting. Now all yogurt labels are required to base their nutrition facts on 175g making it easier to compare between products. 

Figure 1.2.1.6 Foods That Can Be Measured

Foods That Come in Pieces or Are Divided

For foods that come in pieces like crackers, or that come pre-sliced before eating like lasagna, the serving sizes will be presented as either 

• the number of pieces, or
• as a fraction of the food. 

These values will be paired with its weight in grams. Similar products will have the same or very similar gram amounts. 

For example the reference amount for crackers is 20g. Therefore all cracker boxes will have to base their nutrition facts label on the number of crackers that is a close to 20g as possible. Therefore the number of crackers may differ between products but the weight will remain consistent making it easier to compare between products. 

Figure 1.2.1.7 Foods That Come in Pieces or Are Divided

Amount of Foods That Are Typically Eaten

For foods like sliced bread, the serving size will reflect the way it is typically eaten, followed by its weight in grams. 

For example, the serving size on a bag of bread will show 2 slices of bread and its weight in grams. This is because most people eat 2 slices of beard at a time. 

Figure 1.2.1.8 Amounts of Foods That Are Typically Eaten 

Sugars Information

Information on sugar has been change both in the nutrition facts label and in the list of ingredients. 

Nutrition Facts Table

A percent daily value has been added for total sugars to help

• compare the sugar content of different foods and
• identify sugary foods that should be limited, such as those with a daily value of 15% or more.

Figure 1.2.1.9 Sugars Information 

The following table provides examples of the sugars percent daily value for some common food items. 

Foods that are less than 15% daily value of sugar are considered low in sugar and foods that are greater than 15% daily values of sugar are considered high in sugar.

List of Ingredients

All sugars are now listed together, in descending order by weight, after the name ‘sugars’ in ingredient list to help you

• see the sugars that have been added to the food,
• quickly find the sources of sugars added to your food, and
• understand how much sugars are added to the food compared to other ingredients. 

Sugars can include the following: 

• white sugar, beet sugar, raw sugar or brown sugar
• agave syrup, honey, maple syrup, barley malt extract or fancy molasses
• fructose, glucose, glucose-fructose (also known as high fructose corn syrup), maltose, sucrose or dextrose
• fruit juice concentrates and purée concentrates that are added to replace sugars in foods

In Figure 1.2.1.10 there is

• more fancy molasses by weight than brown sugar or sugar, and
• more sugars in the food by weight than any other ingredient.

Figure 1.2.1.10 List of Ingredients: Sugars 

Front-of-Package Nutrition Labeling

Health Canada is in the process of implementing legislation that will require food products to display front-of-package labeling if they are high in sugar, saturated fat or sodium. The proposed thresholds correspond to a percentage of the recommended daily value of sugar, saturated fat and sodium. 

When foods contain a certain amount of a nutrient they are required to have front of package labeling indicating this.

Additional Information on Packaging

There are other types of information that are required by law to appear somewhere on the consumer packaging. They include:^[5]:

• name and address of the manufacturer, packager, or distributor
• statement of identity, what the product actually is
• net contents of the package: weight, volume, measure, or numerical count
• ingredients, listed in descending order by weight

The Nutrition Facts panel provides a wealth of information about the nutritional content of the product. The information also allows shoppers to compare products. Because the serving sizes are included on the label, you can see how much of each nutrient is in each serving to make the comparisons. Knowing how to read the label is important because of the way some foods are presented. For example, a bag of peanuts at the grocery store may seem like a healthy snack to eat on the way to class. But have a look at that label. Does it contain one serving, or multiple servings? Unless you are buying the individual serving packages, chances are the bag you picked up is at least eight servings, if not more.

According to the 2010 health and diet survey released by the FDA, 54 percent of first-time buyers of a product will check the food label and will use this information to evaluate fat, calorie, vitamin, and sodium content ^[6]. The survey also notes that more Americans are using food labels and are showing an increased awareness of the connection between diet and health.