Scientific Report of the 2015 Dietary Guidelines Advisory Committee

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Appendix E-5: Glossary of Terms

AquacultureThe farming of aquatic organisms, including fish, mollusks, crustaceans, and aquatic plants. Farming includes activities to enhance production, such as regular stocking, feeding, and protection from predators.

Acculturation—The process by which immigrants adopt the attitudes, values, customs, beliefs, and behaviors of a new culture. Acculturation is the gradual exchange between immigrants’ original attitudes and behavior and those of the host culture.

Added sugars—Sugars that are either added during the processing of foods, or are packaged as such. They include sugars (free, mono- and disaccharides), syrups, naturally occurring sugars that are isolated from a whole food and concentrated so that sugar is the primary component (e.g., fruit juice concentrates), and other caloric sweeteners. Names for added sugars include: Brown sugar, corn sweetener, corn syrup, dextrose, fructose, fruit juice concentrates, glucose, high-fructose corn syrup, honey, invert sugar, lactose, maltose, malt sugar, molasses, raw sugar, turbinado sugar, trehalose, and sucrose.

Behavioral weight-management program—A structured, multi-component program that encompasses a number of behavior changes, including diet and physical activity with the intent to improve weight (lose weight or maintain weight loss).

Biodiversity—The variety and variability among living organisms and the ecosystems in which they occur. Biodiversity includes the numbers of different items and their relative frequencies; these items are organized at many levels, ranging from complete ecosystems to the biochemical structures that are the molecular basis of heredity. Thus, biodiversity expresses the relative abundance of different ecosystems, species, and genes.

Body mass index (BMI)—A measure defining weight in kilograms (kg) divided by height in meters (m) squared. BMI is an indicator of deficient or excess body tissue, both fat and muscle. BMI status categories include underweight, normal weight, overweight, and obese. (Normal weight is often referred to as “healthy” weight.) Overweight and obese describe ranges of weight that are greater than what is considered healthy for a given height, while underweight describes a weight that is lower than what is considered healthy. Because children and adolescents are growing, their BMI is plotted on growth charts for sex and age. The percentile indicates the relative position of the child's BMI among children of the same sex and age. This is generally referred to as a BMI z-score.

Body Weight Category

Children and Adolescents (ages 2 to 19 years)

(BMIforAge Percentile Range)




Less than the 5th percentile

Less than 18.5 kg/m2

Normal weight

5th percentile to less than the 85th percentile

18.5 to 24.9 kg/m2


85th to less than the 95th percentile

25.0 to 29.9 kg/m2


Equal to or greater than the 95th percentile

Obese class I

30.0 to 34.9 kg/m2

Obese class II

35.0 to 39.9 kg/m2

Obese class III

40.0 kg/m2 and greater

Built environment—The physical form of communities, including urban design (i.e., how a city is designed; its physical appearance and arrangement), land use patterns (i.e., how land is used for commercial, residential, and other activities), and the transportation system (i.e., the facilities and services that link one location to another).

Calorie—A unit commonly used to measure energy content or energy use. It is used as a convenient measure to relate the energy content of food to the energy needs of the body. A calorie is equal to the amount of energy required to raise the temperature of one liter of water 1 degree centigrade. Energy, as measured in calories, is required to sustain the body’s various functions, including metabolic processes and physical activity. Carbohydrate, fat, protein, and alcohol provide all of the energy supplied by foods and beverages.

Carbohydrates—One of the three classes of macronutrients. Carbohydrates include sugars, starches, and fibers:

  • Sugars—A simple carbohydrate composed of one unit (a monosaccharide, such as glucose and fructose) or two joined units (a disaccharide, such as lactose and sucrose). Sugars include white and brown sugar, fruit sugar, corn syrup, molasses, and honey. (See Added sugars)
  • Starches—Many glucose units linked together. Examples of foods containing starch include vegetables, dry beans and peas, and grains (e.g., brown rice, oats, wheat, barley, corn).
  • Fiber—Nondigestible carbohydrates and lignin that are intrinsic and intact in plants. Fiber consists of dietary fiber, the fiber naturally occurring in foods, and functional fiber, which are isolated, nondigestible carbohydrates that have beneficial physiological effects in humans.

Child-care settings—Locations that include child-care centers and child-care provided in homes. Early childhood education settings, such as preschool and Head Start programs, also are included.

Competitive foods—Foods and beverages offered at schools that are sold or offered outside of the Federally reimbursed school lunch and breakfast programs. Competitive foods include food and beverage items sold through à la carte lines, snack bars, student stores, vending machines, and school fundraisers.

Comprehensive lifestyle intervention—Interventions that are designed to address chronic disease risk factors and improve health. They generally include three principal components—a diet component, a physical activity component, and a program of behavior change to facilitate adherence to diet and physical activity recommendations.

Comprehensive lifestyle intervention team—A multidisciplinary team of highly trained professionals, including registered dietitians and nutritionists, exercise specialists, and behaviorists who work with individuals on weight loss or other lifestyle behavior change to improve health and reduce chronic disease risk. (See Interventionist)

Cross-contamination—The spread of bacteria, viruses, or other harmful agents from one surface to another.

Cup equivalent (cup eq)—The amount of a food product that is considered equal to 1 cup from the vegetable, fruit, or milk food group. A cup eq for some foods may differ from a measured cup in volume because (1) the foods have been concentrated (such as raisins or tomato paste), (2) the foods are airy in their raw form and do not compress well into a cup (such as salad greens), or (3) the foods are measured in a different form (such as cheese).

Dietary pattern—The quantities, proportions, variety or combinations of different food and beverages in diets, and the frequency with which they are habitually consumed.

Dietary Reference Intakes (DRIs)—A set of nutrient-based reference values that expand upon and replace the former Recommended Dietary Allowances (RDAs) in the United States and the Recommended Nutrient Intakes (RNIs) in Canada. They include the values shown in the graphic ( and described here:

Graph of observed levels of intake (from risk of inadequacy to risk of adverse effects) for Estimated Average Requirements (EAR), Recommended Dietary Allowance (RDA), and Tolerable Upper Intake Level (UL).

  • Acceptable Macronutrient Distribution Ranges (AMDR)—Range of intake for a particular energy source that is associated with reduced risk of chronic disease while providing intakes of essential nutrients. If an individual’s intake is outside of the AMDR, there is a potential of increasing the risk of chronic diseases and/or insufficient intakes of essential nutrients.
  • Adequate Intakes (AI)—A recommended average daily nutrient intake level based on observed or experimentally determined approximations or estimates of mean nutrient intake by a group (or groups) of apparently healthy people. This is used when the Recommended Dietary Allowance cannot be determined.
  • Estimated Average Requirements (EAR)—The average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and sex group.
  • Recommended Dietary Allowance (RDA)—The average dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals in a particular life stage and sex group.
  • Tolerable Upper Intake Level (UL)—The highest average daily nutrient intake level likely to pose no risk of adverse health effects for nearly all individuals in a particular life stage and gender group. As intake increases above the UL, the potential risk of adverse health effects increases.

Eating out—A behavior that includes meals eaten outside of the home at a variety of venues and takeout or ready-to-eat meals purchased and consumed either away from or in the home.

Empty calories—The calories from components of a food or beverage that contribute few or no nutrients. Major sources of empty calories are solid fats and added sugars. Other sources of empty calories include refined starches (e.g., corn starch, potato starch) and alcohol. In some foods, such as soda and many candies, all the calories are empty calories. However, empty calories also can be found in foods that contain important nutrients. For example, whole milk contains solid fats (butterfat) and sweetened applesauce contains added sugars, which means that some of their calories are empty calories.

Energy drink—A beverage that contains caffeine as a major active ingredient, along with other ingredients, such as taurine, herbal supplements, vitamins, and sugar. It is usually marketed as a product that can improve perceived energy, stamina, athletic performance, or concentration.

Enrichment—The addition of specific nutrients (iron, thiamin, riboflavin, and niacin) to refined grain products in order to replace losses of the nutrients that occur during processing.

Environmental sustainability—Long-term maintenance of ecosystem components and functions for future generations.

Existing reports—Previously published reports or articles that were used as sources of evidence to answer some questions posed by the 2015 DGAC. These sources included reports (e.g., the 2013 American College of Cardiology/ American Heart Association (ACC/AHA) Guidelines on Lifestyle Management to Reduce Cardiovascular Risk), systematic reviews, and meta-analyses. (See Meta-analysis)

Fast food—Foods designed for ready availability, use or consumption and sold at eating establishments for quick availability or take-out. Fast food restaurants are also known as quick-service restaurants.

Fats—One of the three classes of macronutrients. (See Solid Fats and Oils)

  • Monounsaturated Fatty Acids—Monounsaturated fatty acids (MUFAs) have one double bond. Plant sources that are rich in MUFAs include nuts and vegetable oils that are liquid at room temperature (e.g., canola oil, olive oil, high oleic safflower and sunflower oils).
  • Polyunsaturated fatty acids—Polyunsaturated fatty acids (PUFAs) have two or more double bonds and may be of two types, based on the position of the first double bond.
    • n-6 PUFAs—Linoleic acid, one of the n-6 fatty acids, is required because it cannot be synthesized by humans and, therefore, is considered essential in the diet. Primary sources are nuts and liquid vegetable oils, including soybean oil, corn oil, and safflower oil. Also called omega-6 fatty acids.
    • n-3 PUFAs—Alpha-linolenic acid is an n-3 fatty acid that is required because it cannot be synthesized by humans and, therefore, is considered essential in the diet. Primary sources include soybean oil, canola oil, walnuts, and flaxseed. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are very long chain n-3 fatty acids that are contained in fish and shellfish. Also called omega-3 fatty acids.
  • Saturated fatty acids—Saturated fatty acids have no double bonds. Major sources include animal products such as meat and dairy products, and tropical oils such as coconut or palm oils. In general, fats high in saturated fatty acids are solid at room temperature.
  • trans fatty acidsTrans fatty acids are unsaturated fatty acids that contain one or more isolated (i.e., nonconjugated) double bonds in a trans configuration. Sources of trans fatty acids include partially-hydrogenated vegetable oils that have been used to make traditional shortening and some commercially prepared baked goods, snack foods, fried foods, and traditional stick margarine. Trans fatty acids also are present in foods that come from ruminant animals (e.g., cattle and sheep) and are called “natural” or rTFA. Such foods include dairy products, beef, and lamb.

Fight Bac!®—A national public education campaign to promote food safety to consumers and educate them on how to handle and prepare food safely. In this campaign, pathogens are represented by a cartoonlike bacteria character named “BAC.” For more information, visit:

Fishery—An activity leading to harvesting of fish. It may involve capture of wild fish or the raising of fish through aquaculture.

Food access—Accessibility to sources of healthy food, as measured by distance to a store or the number of stores in an area; individual-level resources such as family-income or vehicle availability; and neighborhood-level indicators of resources, such as average income of the neighborhood and the availability of public transportation.

Food categories—A method of grouping similar foods in their as-consumed forms, for descriptive purposes. The USDA/ARS has created 150 mutually exclusive food categories to account for each food or beverage item reported in What We Eat in America (WWEIA), the food intake survey component of the National Health and Nutrition Examination Survey (for more information, visit: Examples of WWEIA Food Categories include soups, nachos, and yeast breads. In contrast to food groups, items are not disaggregated into their component parts for assignment to food categories. For example, all pizzas are put into the pizza category.

Food environments—Factors and conditions that influence food choices and food availability. These environments include settings such as home, child care (early care and education), school, after-school programs, worksites, food retail stores and restaurants, and other outlets where children and their families make eating and drinking decisions. The food environment also includes macro-level factors and includes food marketing, food production and distribution systems, agricultural policies, Federal nutrition assistance programs, and economic price structures.

Food groups—A method of grouping similar foods for descriptive and guidance purposes. Food groups in the USDA Food Pattern are defined as fruits, vegetables, grains, dairy, and protein foods.  Some of these groups are divided into subgroups, such as dark-green vegetables or whole grains, which may have intake goals or limits (for more information, see Appendix E3.1 Table A1. USDA Healthy U.S.-Style Food Patterns—Intake Amounts). For assignment to food groups, mixed dishes are disaggregated into their major component parts. For example, pizza may be disaggregated into the grain (crust), dairy (cheese), vegetable (sauce and toppings), and protein foods (toppings) food groups.

Food pattern modeling—The process of developing and adjusting daily intake amounts from food categories or groups to meet specific criteria, such as meeting nutrient intake goals, limiting nutrients or other food components, or varying proportions or amounts of specific food categories or groups.

Food policies—Regulations, laws, policy-making actions or formal or informal rules established by formal organizations or government units. Food and nutrition policies are those that influence the food environment and eating behavior to improve eating and body weight.

Food security—A condition in which all people, now and in the future, have access to sufficient, safe, and nutritious food to maintain a healthy and active life. (See Household food insecurity)

Fortification—The addition of one or more essential nutrients to a food whether or not it is normally contained in the food for the purpose of preventing or correcting a demonstrated deficiency of one or more nutrients in the population or specific population groups.

Greenhouse gases (GHG)Any gas that absorbs infrared radiation in the atmosphere. Greenhouse gases include carbon dioxidemethane, nitrous oxide, ozone, chlorofluorocarbons, hydrochlorofluorocarbonshydrofluorocarbonsperfluorocarbons, and sulfur hexafluoride.

Health—A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.

Household food insecurity—Circumstances in which the availability of nutritionally adequate and safe food, or the ability to acquire acceptable foods in socially acceptable ways, is limited or uncertain.

  • Persistent household food insecurity—Occurs when people are unable to meet their minimum food requirements over a sustained period of time.
  • Progressing household food insecurity—A change in situation from food secure to food insecure or from acute or temporary food insecurity to persistent food insecurity.
  • Household food insufficiency—A similar measure to food insecurity considered more severe than the concept of food security, although not as severe as hunger.

Interventionist—Trained health professionals (e.g., registered dietitians, psychologists, exercise physiologists, health counselors, or professionals in training) who adhere to formal protocols in providing healthy lifestyles counseling and treatment, such as for weight management. In a few cases, lay persons are used as trained interventionists; they received instruction in protocols (designed by health professionals) for programs that have been validated in high-quality trials and published in peer-reviewed journals.

Isocaloric—Having the same caloric values. For example, two dietary patterns that vary in macronutrient proportions but have the same calorie content are isocaloric.

Lean meat—Any meat with less than 10% fat by weight, or less than 10 grams of fat per 100 grams, based on USDA and FDA definitions for food label use. Examples include 95% lean ground beef, cooked; broiled beef steak, lean only eaten; baked pork chop, lean only eaten; roasted chicken breast or leg, no skin eaten; and smoked/cured ham, lean only eaten.

Life Cycle Assessment (LCA)—A technique for assessing the biophysical environmental aspects and potential impacts associated with a product, by:

  • Compiling an inventory of relevant inputs and outputs of a product system;
  • Evaluating the potential environmental impacts associated with those inputs and outputs;
  • Interpreting the results of the inventory analysis and impace assessment phases in relation to the objectives of the study.

LCA studies the environmental aspects and potential impacts throughout a product’s life (i.e., cradle to grave), from raw material acquisition through production, use, and disposal. The general categories of environmental impacts needing consideration include resource use, human health, and ecological consequences.

Macronutrient—A dietary component that provides energy. Macronutrients include protein, fats, and carbohydrates. Alcohol also provides energy but, for purposes of the DGAC report, it is not considered when discussing macronutrients.

Meta-analysis—The statistical analysis of multiple individual studies for the purpose of integrating the findings and deriving conclusions from the body of literature.  

Mobile Health (mHealth)—The use of mobile and wireless technologies to support the achievement of health objectives.

Moderate alcohol consumption—Average daily consumption of up to one drink per day for women and up to two drinks per day for men, with no more than three drinks in any single day for women and no more than four drinks in any single day for men. One drink is defined as 12 fl. oz. of regular beer, 5 fl. oz. of wine, or 1.5 fl. oz. of distilled spirits.

Nutrient-dense foods—Foods that are naturally rich in vitamins, minerals, and other substances that may have positive health effects, and are lean or low in solid fats and without added solid fats, sugars, starches, or sodium and that retain naturally-occurring components such as fiber. All vegetables, fruits, whole grains, fish, eggs, and nuts prepared without added solid fats or sugars are considered nutrient-dense, as are lean or low-fat forms of fluid milk, meat, and poultry prepared without added solid fats or sugars. Nutrient-dense foods provide substantial amounts of vitamins and minerals (micronutrients) and relatively few calories compared to forms of the food that have solid fat and/or added sugars.

Nutrition Evidence Library (NEL) systematic review—A process that uses state-of-the-art methodology to search, evaluate, and synthesize food and nutrition-related research. This rigorous, protocol-driven methodology is designed to minimize bias, maximize transparency, and ensure relevant, timely, and high-quality systematic reviews to inform Federal nutrition-related policies, programs, and recommendations. The NEL is a division of the USDA Center for Nutrition Policy and Promotion. For more detailed information, visit:

Oils—Fats that are liquid at room temperature. Oils come from many different plants and some fish. Some common oils include canola, corn, olive, peanut, safflower, soybean, and sunflower oils. A number of foods are naturally high in oils, such as: nuts, olives, some fish, and avocados. Foods that are mainly made up of oil include mayonnaise, certain salad dressings, and soft (tub or squeeze) margarine with no trans fats. Oils are high in monounsaturated or polyunsaturated fats, and lower in saturated fats than solid fats. A few plant oils, termed tropical oils, including coconut oil, palm oil and palm kernel oil, are high in saturated fats and for nutritional purposes should be considered as solid fats. Partially-hydrogenated oils that contain trans fats should also be considered as solid fats for nutritional purposes. (See Fats)

Ounce equivalent (oz eq)—The amount of a food product that is considered equal to one ounce from the grain or protein foods food group. An oz eq for some foods may be less than a measured ounce in weight if the food is concentrated or low in water content (nuts, peanut butter, dried meats, flour) or more than a measured ounce in weight if the food contains a large amount of water (tofu, cooked beans, cooked rice or pasta).

Persistent organic pollutants (POPs)—Toxic chemicals that can adversely affect human health and the biophysical environment. Because they can be transported by wind and water, most POPs generated in one country may affect people and wildlife distant to where they are used and released. They can persist for long periods of and can accumulate and pass from one species to the next through the food chain.

Plant-based foods—Foods such as vegetables, fruits, whole grains, nuts and seeds.

Point-of-purchase—A place where sales are made. Various intervention strategies have been proposed to affect individuals’ purchasing decisions at the point of purchase, such as board or menu labeling with various amounts of nutrition information or shelf tags in grocery stores.

Portion size—The amount of a food served or consumed in one eating occasion. A portion is not a standardized amount, and the amount considered to be a portion is subjective and varies.

Processed meat—Meat, poultry, or seafood products preserved by smoking, curing or salting, or addition of chemical preservatives. Processed meat includes bacon, sausage, hot dogs, sandwich meat, packaged ham, pepperoni, and salami.

Protein—One of the three macronutrients classes. Protein is the major functional and structural component of every animal cell. Proteins are composed of amino acids, nine of which are indispensable, meaning they cannot be synthesized by humans and therefore must be obtained from the diet. The quality of dietary protein is determined by its amino acid profile relative to human requirements as determined by the body's requirements for growth, maintenance, and repair. Protein quality is determined by two factors: digestibility and amino acid composition.

  • Animal protein—Protein from meat, poultry, seafood, eggs, and milk and milk products.
  • Vegetable protein—Protein from plants such as dry beans, whole grains, fruit, nuts, and seeds.

Refined grains—Grains and grain products missing the bran, germ, and/or endosperm; any grain product that is not a whole grain. Many refined grains are low in fiber but enriched with thiamin, riboflavin, niacin, and iron, and fortified with folic acid.

Screen time—Time in front of a computer, television, video or computer game system, or smart phone or tablet or related device.

Seafood—Marine animals that live in the sea and in freshwater lakes and rivers. Seafood includes fish, such as salmon, tuna, trout, and tilapia, and shellfish, such as shrimp, crab, and oysters.

Sedentary behavior—Any waking activity predominantly done while in a sitting or reclining posture. A behavior that expends energy at or minimally above a person’s resting level (between 1.0 and 1.5 metabolic equivalents), is considered sedentary behavior.

Self-monitoring—Self-monitoring refers to the process by which an individual observes and records specific information about his or her behaviors. For example, in weight management self-monitoring, observations and records would reflect dietary intake, physical activity, and/or body weight.

Solid fats—Fats that are usually not liquid at room temperature. Solid fats are found in animal foods except for seafood, and can be made from vegetable oils through hydrogenation. Some tropical oil plants, such as coconut and palm, are considered as solid fats due to their fatty acid composition. Solid fats contain more saturated fats and/or trans fats than liquid oils (e.g., soybean, canola, and corn oils), with lower amounts of monounsaturated or polyunsaturated fatty acids. Common fats considered to be solid fats include: butterfat, beef fat (tallow, suet), chicken fat, pork fat (lard), stick margarine, shortening, coconut oil, palm oil and palm kernel oil. Foods high in solid fats include: butter, full-fat cheeses, creams, whole milk, full fat ice creams, marbled cuts of meats, regular ground beef, bacon, sausages, poultry skin, and many baked goods made using these products (such as cookies, crackers, doughnuts, pastries, and croissants).The fat component of milk and cream (butter) is solid at room temperature. (See Fats)

Sugar-sweetened beverages—Liquids that are sweetened with various forms of added sugars (see Added Sugars and Carbohydrates: Sugars). These beverages include, but are not limited to, soda, fruitades, and sports drinks. Also called calorically-sweetened beverages.

Sustainable diets—A pattern of eating that promotes health and well-being and provides food security for the present population while sustaining human and natural resources for future generations.

Trophic level—A functional classification of species that is based on feeding relationships. Generally, aquatic and terrestrial green plants comprise the first, or lowest, trophic level, herbivores comprise the second, and primary carnivores comprise the third, or highest level. Examples of high trophic fish species are salmon and trout. Low trophic fish species include crayfish and catfish.

Whole grains—Grains and grain products made from the entire grain seed, usually called the kernel, which consists of the bran, germ, and endosperm. If the kernel has been cracked, crushed, or flaked, it must retain the same relative proportions of bran, germ, and endosperm as the original grain in order to be called whole grain. Many, but not all, whole grains are also sources of dietary fiber.