Our Algorithms

The Guiding Stars algorithms are patented, which allows us to be fully transparent about our product evaluations.

What are the Guiding Stars algorithms?

An algorithm is a set of rules that we follow in order to calculate how many Guiding Stars a food earns. We use four separate algorithms to evaluate different categories of foods: General Foods & Beverages; Meats, Poultry, Seafood, Dairy & Nuts; Fats & Oils; and Infant & Toddler Foods. These categories are evaluated with distinct criteria to account for inherent differences in their nutritional composition and the role that those foods play in our diets. Our algorithms are designed to rigorously evaluate the nutrient density of foods within a category. They were created by a Scientific Advisory Panel which includes experts in nutrition, medicine, biochemistry, and public health. Our Scientific Advisors review the latest nutrition science and when new findings are supported by consensus, as reflected in new policy and guidelines, our algorithms are updated.

Request the white paper about our algorithms »

Nutrient Density and Data Standardization

Serving sizes on packaged and prepared foods and across food groups vary significantly. In order to determine nutrient density between different kinds of foods, we look at a 100-calorie portion of the food. This allows us to fairly compare across foods in all food categories. We then evaluate the nutrients in that portion of the food.

Nutrients We Consider

We assign positive or negative points to foods. Nutrients to encourage receive positive points, and nutrients to limit or avoid receive negative points.

Nutrients We Don’t Consider

There are many reasons why some food nutrients or ingredients are not included in our algorithms. It may be because the nutrient is not associated with a significant health benefit or adverse effect or that it is not included on the food label. As new research emerges and food labels are updated to reflect current scientific consensus and nutritional policy, the Guiding Stars algorithms will likewise be updated to reflect the current dietary recommendations.

How a Food Earns Stars

We total the positive and negative points for nutrients to understand the overall nutrition a food provides. If a food has a positive score, or more of the nutrients to encourage, then it earns 1, 2, or 3 Guiding Stars. Foods that have a negative score don’t earn Guiding Stars. That doesn’t mean they are bad, but that they should be consumed in moderation and paired with star earning foods to balance your meal or snack.

Keywords

To avoid penalizing foods that contain naturally-occurring sugars or sodium (e.g., milk and spinach, respectively), we look for keywords in the ingredients lists that indicate added sugars or sodium. Keywords are also used to identify key whole grains and artificial colors.

What We Evaluate

We evaluate all foods with more than five calories per serving at no cost to the manufacturer. This includes national, regional, and store-brand products. This ensures that you can easily compare the stars of all products, that cost is not a barrier, and that our clients’ products are not highlighted over an equally nutritious national brand product. We use the same objective criteria to evaluate all of these foods and beverages. It should go without saying, but manufacturers can’t buy a star.

Our Algorithms

Due to intrinsic differences in the composition of foods, our Scientific Advisory Panel developed several algorithms to evaluate certain categories with more specific and fine-tuned criteria. With the exception of the Infant and Toddler Foods algorithm, all algorithms are based on a 2,000 calorie per day diet and the U.S. Dietary Guidelines for adults and children over the age of 2.

For specific details on how we calculate points for each algorithm, request our white paper (PDF).

General Foods & Beverages

Our primary algorithm works well for most foods and drinks. This algorithm is used to evaluate fruits, vegetables, cereals & grains, legumes, beverages (other than dairy-based beverages), snack foods, and mixed foods such as a burrito or pasta dish that contains foods from a variety of food groups.

Meats, Poultry, Seafood, Dairy & Nuts

These foods are naturally higher in certain kinds of fats and generally do not contain dietary fiber, with the exception of nuts. The FDA has different guidelines for meat and seafood regarding saturated fats, and the Dietary Guidelines classify nuts with meats.

Fats & Oils

A separate fats and oils model was created because the other algorithms did not originally include nutrients such as omega-3 fatty acids (which include alpha-linolenic acid, eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and monounsaturated fatty acids (MUFA) that must be considered to differentiate fats and oils in a meaningful way. Beyond the typical fats and oils such as butter or vegetable oil, we also use this algorithm to evaluate oil-based products such as salad dressings and mayonnaise.

Infant & Toddler Foods

A separate algorithm was created to evaluate infant and toddler foods to reflect the unique nutritional needs of this age group. This algorithm is consistent with the others in that it uses a 100-calorie standardization, but it references a 1000-calorie diet as its base as per the American Academy of Pediatrics’ recommendations for children under the age of 2.

Foods Ineligible for Guiding Stars

As mentioned above, we evaluate most edible foods in the store. We only display a rating if an item earns 1, 2, or 3 stars so as not to shame foods that don’t earn a star. If you don’t see the Guiding Star icon, it means the item doesn’t earn a star. There are, however, three exceptions to this rule:

• Foods that have five calories or less per serving (such as bottled water and spices) are not evaluated by the Guiding Stars program.
• Medical foods, vitamins, and supplements are not evaluated because we recognize that decisions about including these foods in your diet should be made with the help of your doctor.
• Infant formula is not evaluated by the Guiding Stars program. The composition of infant formula is highly regulated and thus is more of a medical food for this reason. We also feel strongly that the decision about the use of formula or breastfeeding is a personal one that should be made by individuals with the help of their child’s pediatrician.

Algorithm Updates

• Feb. 7, 2019 – The algorithm now treats juice concentrate as an added sugar.
• Feb. 1, 2018 – The algorithm now gives a credit for omega-3 fatty acids and DHA & EPA and a debit for artificial colors.
• Jun. 8, 2016 – The algorithm eliminates debits for most foods containing cholesterol.