With thousands of food choices at your local store it can be difficult to know if you are choosing foods that are truly good for you. In recent years there have been several types of nutrient rating systems derived to help you make better choices — but have you found yourself asking whether or not they are actually helpful? Find out what all those numbers really mean.
Glycemic Index: Measures how quickly food is metabolized into glucose when digested. The G.I. also estimates how much each gram of available carbohydrate (this equals total carbohydrates minus fiber, which is non-digestible) in a food raises a person’s blood glucose level following consumption of the food.
Examples: Glucose has a glycemic index of 100; all other foods have lower glycemic indexes.
Pros: Helpful for diabetics and those counting carbs.
Cons: Not as informative regarding fats and proteins.
Guiding Stars: Rates foods using stars. Scores range from zero to three stars, with three being the healthiest. Classifies foods as “good, better or best.” The ratings are based on the nutrient density of each food. This system has been adopted by specific grocery stores, namely Hannaford, Food Lion, Bloom and Sweetbay. About ¼ of the 50,000 items in these stores have Guiding Stars ratings.
Examples: Sugary cereals have fewer stars; leaner meats have more stars.
Pros: The star system is easy to understand.
Cons: Not highly detailed, depends on where you shop and what you buy.
Overall Nutritional Quality Index (ONQI): Evaluates foods on a 1-to-100 scale; 100 is the healthiest. ONQI score formula includes 30 different factors. It assigns greater value to some nutrients, particularly those that are associated with specific health outcomes (cancer, heart disease, etc.). Also gives value to glycemic load, energy density and protein quality in addition to nutrients that have no official RDI (recommended daily intake), including omega-3 fatty acids, bioflavonoids and carotenoids.
Examples: Mustard greens and strawberries have a score of 100, salmon gets an 87, and soda receives a 1.
Pros: Considers many aspects and qualities of food
Cons: More useful for whole foods; not brand specific
NuVal: Scores summarize comprehensive nutritional information in one number between 1 and 100. Each NuVal Score considers 30+ nutrients and nutrition factors. These scores are acquired using the ONQI algorithm and applied to commercial products. This includes beneficial nutrients (protein, calcium, vitamins) and detrimental factors (sugar, sodium, cholesterol). Vitamins and minerals increase NuVal scores, while fats, sugar and cholesterol lower it. NuVal includes some factors that ANDI does not (Vitamins A and D, potassium, etc.) and rates items by brand and type.
Examples: Fresh broccoli scores 100; canned spinach 82; baked Lays chips 24; Nabisco Nilla wafers 6
Pros: Comprehensive, considers a variety of factors, plus it rates brand-specific items.
Cons: May not fit all diets and/or lifestyles.
Aggregate Nutrient Density Index (ANDI): The highest score is 1000; the lowest is close to zero. In addition to a range of micronutrients like calcium, beta-carotene, fiber, folate, iron, magnesium, vitamins B6, B12, vitamin C, vitamin E, zinc, ANDI also uniquely considers niacin, selenium, vitamins B1 (thiamin), and B2 (riboflavin) as well as ORAC scores (Oxygen Radical Absorbance Capacity). ORAC measures the antioxidant or radical scavenging capacity of foods. ANDI is the system of choice at Whole Foods Markets and evaluates about 500 products. The general equation is Health = Nutrients/Calories.
Examples: Kale is 1000, carrots score 240, walnuts are 34, and cola is 0.6.
Pros: Nutritionally comprehensive; gives value to preventative nutrients.
Cons: Depends where you shop; just one number may not explain nutritive intricacies.
Naturally Nutrient Rich (NNR): Though still being refined, NNR score researchers are working closely with the USDA. This system may become national, as the USDA makes direct reference to the NNR. Instead of offering scores and organizing by brand or product, NNR offers consumers recommended nutrient-rich whole foods organized by food group. NNR gives equal value to the 14 nutrients that make up its formula. Guidelines are general. This may be due to the role commodity associations play (eg: National Dairy Council, Wheat Foods Council, etc.) in the system.
Examples: Recommends whole foods; discourages processed and/or junk foods.
Pros: Approved by the USDA.
Cons: Does not use numeric rating; may be overly generalized.
Take Away Messages: You may notice some recurring themes throughout these systems. Many are numerical, often on a 1 to 100 scale. It is not unusual for a grocery store or chain to commit to a single system. Data for whole foods such as produce, grains and legumes is relatively easy to analyze based on USDA standards. Beware: it is much more complicated to get accurate info for packaged or processed foods. The ingredients in processed food may interact with each other and change the nutrition profile of a product.
What do you think about nutrient rating systems? Helpful or not?