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The George Mateljan Foundation, a not-for-profit foundation with no commercial interests, is a new force for change to help make a healthier you and a healthier world.

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Our Food and Recipe Rating System

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Why did we rate our foods and recipes?

We rated our foods and recipes to give you an extremely fast, simple, yet highly reliable way to meet your personal nutrition needs. Are you looking for foods that are richest in zinc? Or recipes that are highest in fiber? We wanted you be able to access any nutritional information of this kind with a click of your mouse button.

Where did we start?

We began with a computerized analysis of the nutritional contents of the World's Healthiest Foods. In other words, we started with a food like carrots, and we analyzed how much vitamin C, vitamin A, zinc, protein, etc. that food contained in one commonly-eaten serving. We repeated this process until we analyzed 30 different nutrients for each of our 125 healthiest foods.

What kind of categories did we establish for ranking foods?

We picked a simple, three-category system for ranking all foods. The three categories we chose were "good," "very good," and "excellent." We decided to develop a ranking process that would let us separate "good" food sources of a nutrient from "very good" sources, and "very good" sources of a nutrient from "excellent" ones. We assumed you would not want to know about the nutritional quality of a food if it didn't rise up to at least the "good" level.

How did we decide which foods were "good," "very good," and "excellent" sources of nutrients?

We developed a two-part formula to determine how "good" a food was as a source of nutrients. The first (and most important) part of this formula looked at the nutrient density of each food. Nutrient density is a key idea in nutritional science. It compares the nutritional content of a food to its calorie content. If a food is very high in one or more nutrients, but very low in calories, it can be described as "nutrient dense" because it uses up very little of your day's calories but is still "thick" with nutrients. If a food is low in nutrients but high in calories, it is the opposite of nutrient dense - we could describe it with the words "nutrient sparse" or "nutrient thin." A "nutrient thin" food gives you very little in terms of nutrition, but uses up a lot of your day's calories. Many foods fall somewhere in the middle and are considered "average" in terms of density. They give you a fair number of nutrients and use up a fair number calories; or they give you a lot of nutrients and use up a lot of calories. We didn't think you would want to know about the "nutrient thin" or average foods, but only those foods that were nutrient dense and provided you with lots of nutrients while costing you few calories.

With the categories of "good," "very good," and "excellent," in hand, and our thinking focused on nutrient density, we developed specific density criteria for each of our three categories. To qualify as a "good" source of nutrients, we decided that a food should have a density value of at least 1.5. In other words, that food had to give you 1.5 times as much nutrition as calories. Or to put it slightly differently, it had to give you 50% more in nutrition than it used up in calories.

Let's take a real-life example. One-quarter cup is a commonly-eaten snack portion of nuts or seeds, so we took one quarter cup of sunflower seeds as our starting point for ranking this food. That quarter cup of sunflower seeds was determined to have about 200 calories (205 to be exact), and those 205 calories were about 11% of a 2,000-calorie daily diet. Were sunflower seeds a "good" source of any nutrient? We used our 1.5 criterion to help us decide. Since those 205 calories' worth of sunflower seeds provided about 11% of a day's calories, they had to provide at least 1.5 times that much of some nutrient to qualify as a "good" source of that nutrient. Did one-quarter cup of sunflower seeds supply at least 17% of the daily requirement for some nutrient? The answer was yes! While using up only 11% of the day's calories, it provided over 20% of the daily value for folate and vitamin B5; and over 25% for phosphorus, tryptophan, copper, magnesium, and mangenese.

We moved our criterion up to 3.4 to help us decide if a food was a "very good" source of a nutrient. In other words, we said that whatever percentage of a day's calories a food supplied, it had to supply 3.4 times that much in a nutrient in order for it to qualify as a "very good" source. To go back to our real-life example: our quarter cup of sunflower seeds still supplied 205 calories or about 11% of a day's calories. But how did it do as a "very good" source of nutrients? Did it provide at least 3.4 times that much of any nutrient, i.e., at least 38% of the daily value? The answer once again was yes! One-quarter cup of sunflower seeds provided over 38% of a day's vitamin B1 need.

Finally, to help us decide if a food could be called an "excellent" source of a nutrient, we moved our criterion up again from 3.4 to 7.6. Whatever percentage of a day's calories a food supplied, we said it had to supply 7.6 times that much in a nutrient in order for it to be considered an "excellent source." We knew that our quarter cup of sunflower seeds provided about 11% of a day's calories? But did they provide 7.6 that much in any nutrient, i.e., 86% of the daily value? Once again, the answer was yes! Our quarter cup of sunflower seeds provided over 90% of the daily value for vitamin E, making sunflower seeds an "excellent" source of this nutrient.

In order to give you an easy-to-follow context in presentation of our Food and Recipe Rating System, we've used the phrases "Daily Value" or "DV" or "% Daily Value" to describe the amounts of nutrients that our foods and recipes provide. The way we arrive at actual values in our food and recipe charts is a little more complicated than these phrases imply, and the details are as follows:

In a strictly technical sense, the term "Daily Value" (DV) refers to a standard that is set by the U.S. Food and Drug Administration (FDA) for use on the Nutrition Facts Panel of a packaged food. The FDA describes DVs as "reference values for nutrition labeling." From the FDA's perspective, DVs are a way to provide consumers with an easy-to-follow set of nutritional guidelines. They are a "one size fits all" set of standards. Men and women as well as older and younger consumers are all subject to the same DV set of standards. We like the simple and easy-to-follow nature of the DVs, and so we adopted them for use in our rating system as much as possible.

Here are the nutrients that have FDA Daily Value (DV) standards in our rating system, listed with their DV in parentheses:

Vitamins

Minerals

Macronutrients

The FDA has not established Daily Values (DVs) for monounsaturated or polyunsaturated fat. However, we used the DVs for total fat (65 grams) and saturated fat (20 grams) to derive our rating system standards for these two types of unsaturated fat. We subtracted saturated fat grams from total fat grams and divided up the remaining 45 grams of unsaturated fat into equal amounts of 22.5 grams for monounsaturated fat and 22.5 grams for polyunsaturated fat.

While these DVs from the FDA served as a great foundation for our food and recipe rating system, we ran into problems with the FDA's standards in two areas. First, there were nutrients we wanted to evaluate in our foods and recipes that did not have DV standards from the FDA. Second, in the case of calories, we did not want to set our calorie comparison level at the FDA's DV level of 2,000 calories. We believed that the calorie standard should be set a little lower than 2,000 to provide the best general guideline for our website visitors. Given these two problem areas, we ended up with a set of rating system standards in which approximately two-thirds of our nutrient standards (those listed above) are exact DVs established by the FDA, and approximately one-third of our nutrient standards come from two other health organizations that have established public health guidelines in the area of nutrition. The two other organizations we used as sources for the remaining third of our rating system standards were: (1) the Institute of Medicine at the National Academy of Sciences (NAS), which issues the Dietary Reference Intakes (DRIs) and provides the "gold standard" set of guidelines for use by registered dietitians and other healthcare professionals both inside and outside of the United States; and (2) the National Institutes of Health (NIH), which in 1999 conducted a special workshop entitled, "Workshop on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega-3 Fatty Acids" and provided a unique and detailed set of guidelines with respect to omega-3 fatty acid intake. A table showing our nutrient components with DRIs from the National Academy of Sciences appears below:
NutrientDRI StandardFurther Description
calories1800 kcal EER for sedentary female 31-50yo (2002 DRIs, very similar but not identical to the most recent 2005 DRIs for calories)td>
choline425 mcgcurrent DRI for all adults
fluoride 3 mg current DRI for all adults
cystine0.625 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 12.5 mg/g of protein and protein DV of 50g (the DRI is 25mg/g for cystine plus methionine combined which we allocated 50%-50%)
histidine0.9 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 18 mg/g of protein and protein DV of 50g
isoleucine1.25 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 25 mg/g of protein and protein DV of 50g
leucine2.75 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 55 mg/g of protein and protein DV of 50g
lysine2.55 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 51 mg/g of protein and protein DV of 50g
methionine0.625 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 12.5 mg/g of protein and protein DV of 50g (the DRI is 25mg/g for cystine plus methionine combined which we allocated 50%-50%)
phenylalanine1.175 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 23.5 mg/g and protein DV of 50g (the DRI is 47mg/g for phenylalanine plus tyrosine combined which we allocated 50%-50%)
threonine1.350 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 27 mg/g of protein and protein DV of 50g
tryptophan0.350 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 7 mg/g of protein and protein DV of 50g
tyrosine1.175 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 23.5 mg/g of protein and protein DV of 50g (the DRI is 47mg/g for phenylalanine plus tyrosine combined which we allocated 50%-50%)
valine1.600 g amino acid, calculated for 31-50yo female based on 2002 DRI value of 32 mg/g of protein and protein DV of 50g

When using the DRI standards, we selected the NAS recommendations for adult women ages 31-50 whenever the standards for a nutrient varied by age and/or gender for adults. In the case of calories, we selected the NAS recommendation of 1,800 calories for adult women, ages 31-50, with a sedentary physical activity level, as set forth in the 2002 Dietary Reference Intakes established for macronutrients (protein, carbohydrates, and fats) and energy (calories). While we recognize that in 2005 the NAS issued a revised set of guidelines for calories, when we checked into that revised set of guidelines, we found that the new guideline for adult women, ages 31-50, with a sedentary physical activity level, a median height of 5'5", and a body mass index (BMI) of 18.5 was 1,816 calories. Since that level was very close to the 1,800 level in the 2002 DRI recommendations, we stuck with 1,800 calories as our rating standard.

In the case of amino acids, we used the recommended protein digestibility corrected amino acid scoring pattern (PDCAAS) as published in the 2005 Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) - published once again by the National Academy of Sciences in Washington, D.C. We took these PDCAAS guidelines and applied them to the FDA's DV for protein (50 grams) in order come up with rating standards for 11 amino acids.

With respect to omega-3 fatty acids, we adopted the standards set forth in a 1999 workshop conducted at the National Institutes of Health (NIH). This workshop, entitled "Workshop on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega-3 Fatty Acids," was convened to develop science-based, public-health recommendations for omega-3 fatty acids, and it included a prestigious group of health researchers and was led by Artemis Simopolous, MD, Alexander Leaf, MD, and Norman Salem, Jr., PhD. The workshop concluded that at least 1.2% of daily calories should come from omega-3 fatty acids, including 1% from alpha-linolenic acid and 0.1% each from EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) When translated into the context of an 1800-calorie diet, this workshop standard represented a recommendation of 2.4 grams of omega-3 fatty acids per day, which we adopted as our food and recipe rating system standard. We recognize the fact that in 2005, the National Academy of Sciences (NAS) set an Adequate Intake (AI) level for one particular omega-3 fatty acid (alpha-linolenic acid). This AI was set at 1.6 grams per day for all adults. However, since the NAS did not address unique roles played by other omega-3 fatty acids, including EPA or DHA, we determined the NIH workshop results to provide a more complete standard for rating the omega-3 content of our foods and recipes.

When you read the %DV for any nutrient found in a World's Healthiest Food or Recipe, you are getting an evaluation of the nutrient value in the food or recipe that is based on very high research standards set forth by the leading government agencies that are involved with food, nutrition, and health. You are also getting a more comprehensive look at the nutritional value of a food or recipe than could be obtained from a Nutrition Facts Panel!

Why turnip greens, mustard greens, and tofu are ranked as better sources of calcium than dairy products

For example, our food ranking system shows turnip greens, mustard greens, and tofu to be better sources of calcium than dairy products. We arrive at this conclusion since our ranking system looks not only at the amount of calcium in food but also at the caloric content of food and how many calories of a food are necessary to provide the desired amount of calcium. Dairy foods - which are often listed as excellent sources of calcium - turn out to be very good sources of calcium in our ranking system (just one step below turnip greens, mustard greens, and tofu) because of their lower nutrient density.

Should I only eat foods with the highest scores?

No! Even though foods with high scores are the most nutrient dense and give you more nutrients for fewer calories, all of the foods featured on this website have unique nutritional value. Many foods with lower scores can complement each other perfectly to round out your total nourishment. At the same time, however, if you find yourself eating exclusively at the lower end of the ranked foods, you may want to consider experimenting with recipes that can bring more highly ranked foods into your diet.

References