Position Paper Position of the Academy of Nutrition and Dietetics : Dietary Fatty Acids for Healthy Adults

It is the position of the Academy of Nutrition and Dietetics (the Academy) that dietary fat for the healthy adult population should provide 20% to 35% of energy, with an increased consumption of n-3 polyunsaturated fatty acids and limited intake of saturated and trans fats. The Academy recommends a food-based approach through a diet that includes regular consumption of fatty fish, nuts and seeds, lean meats and poultry, low-fat dairy products, vegetables, fruits, whole grains, and legumes. These recommendations are made within the context of rapidly evolving science delineating the influence of dietary fat and specific fatty acids on human health. In addition to fat as a valuable and calorically dense macronutrient with a central role in supplying essential nutrition and supporting healthy body weight, evidence on individual fatty acids and fatty acid groups is emerging as a key factor in nutrition and health. Small variations in the structure of fatty acids within broader categories of fatty acids, such as polyunsaturated and saturated, appear to elicit different physiological functions. The Academy recognizes that scientific knowledge about the effects of dietary fats on human health is young and takes a prudent approach in recommending an increase in fatty acids that benefit health and a reduction in fatty acids shown to increase risk of disease. Registered dietitian nutritionists are uniquely positioned to translate fat and fatty acid research into practical and effective dietary recommendations. J Acad Nutr Diet. 2014;114:136-153. POSITION STATEMENT It is the position of the Academy of Nutrition and Dietetics that dietary fat for the healthy adult population should provide 20% to 35% of energy, with an increased consumption of n-3 polyunsaturated fatty acids and limited intake of saturated and trans fats. The Academy recommends a food-based approach through a diet that includes regular consumption of fatty fish, nuts and seeds, lean meats and poultry, low-fat dairy products, vegetables, fruits, whole grains, and legumes. a HIS IS AN UPDATE OF THE (TFA) for healthy individuals. From ways that are difficult to delineate. T2007 Dietary Fatty Acid Position Paper developed by the Academy of Nutrition and Dietetics (the Academy; formerly the American Dietetic Association) and the Dietitians of Canada. This update and the associated position reflect the current opinions of the Academy and is based on the most current scientific literature with consideration of other academic or organizational body recommendations. The objectives of the current position paper are to provide information on specific fatty acids including structure, current and recommended intakes, function, and impact on health. This position paper evaluates the evidence for both beneficial and adverse effects of dietary fatty acids for the purpose of providing a rationale for intake levels of total fat, n-3 and n-6 polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), saturated fatty acids (SFA), and trans-fatty acids this, a position has been developed that will guide registered dietitian nutritionists (RDNs) in their practice and dietetic technicians, registered (DTRs) who work under the supervision of the RDN in counseling healthy individuals. As the stated position reflects recommendat ions for fat ty ac id intakes in the context of healthy individuals, it will not provide dietary guidance for chi ldren, pregnant women, or specific disease states. Fatty acids are the major form of dietary fat and primarily exist in foods in the triglyceride form. Although fatty acids are often categorized by their saturation status (eg, monounsaturated, saturated), understanding the role of individual fatty acids on health, rather than as a group, is important. Because of this, fatty acids will be presented individually in the following order: polyunsaturated, monounsaturated, saturated, and trans. In addition, fatty acids are consumed as a part of foods that contain other nutrients and dietary compounds; these have both additive and synergistic effects on health and interact in complex 2 Therefore, the roles of individual fatty acids within the broader context of food and dietary patterns will be discussed. FATTY ACID CLASSIFICATION SYSTEM Fatty acid structures vary considerably by both hydrocarbon chain length and saturation status. Although carbon chain length can vary from 2 to 40 carbons, most dietary fatty acids contain 12 to 22 carbons. Fatty acids are often categorized into short chain (up to 6 carbons), medium chain (8 to 12 carbons), or long chain (>12 carbons). Although hydrocarbon chain length is an important determinant of function, fatty acids are often classified based on whether or not the fatty acid carbon chain contains no double bonds (SFA), one double bond (MUFA), or more than one double bond (PUFA), as well as the configuration of the double bonds (cis or trans). In addition, PUFAs are often further classified based on the position of the first double bond from the fatty acid methyl terminus, creating n-3 and n-6 fatty acids. In n-3s, the first double 014 by the Academy of Nutrition and Dietetics. This Academy of Nutrition and Dietetics position paper includes the authors’ independent review of the literature in addition to a systematic review conducted using the Academy’s Evidence Analysis Process and information from the Academy’s Evidence Analysis Library. Topics from the Evidence Analysis Library are clearly delineated. The use of an evidence-based approach provides important added benefits to earlier review methods. The major advantage of the approach is the more rigorous standardization of review criteria, which minimizes the likelihood of reviewer bias and increases the ease with which disparate articles can be compared. For a detailed description of the methods used in the Evidence Analysis Process, go to www. andevidencelibrary.com/eaprocess. Conclusion Statements are assigned a grade by an expert work group based on the systematic analysis and evaluation of the supporting research evidence: Grade I[Good Grade II[Fair Grade III[Limited Grade IV[Expert Opinion Only Grade V[Not Assignable (because there is no evidence to support or refute the conclusion). See grade definitions at: www. andevidencelibrary.com. Evidence-based information for this and other topics can be found at www. andevidencelibrary.com. Subscriptions for nonmembers are purchasable at: www.andevidencelibrary.com/store.cfm. FROM THE ACADEMY bond occurs at the third carbon of the fatty acid chain from the methyl (or omega) end, and in n-6s, the first double bond occurs at the sixth carbon in the fatty acid chain. Figure 1 presents nomenclature and common food sources of dietary fatty acids. It is the differences in chain length and saturation status that dictate their performance in food and cooking, as well as their role in the body and impact on human health and disease risk. TOTAL FAT VS INDIVIDUAL FATTY ACIDS Total fat intake has been the primary focus of dietary recommendations, with increased emphasis on the health impact of individual fatty acids in recent years. Total fat intake of 20% to 35% of energy is recommended by the Institute of Medicine and the Food and Agriculture Organization of the United January 2014 Volume 114 Number 1 Nations (FAO) and is supported by the 2010 Dietary Guidelines for Americans (DGA). The American Heart Association (AHA) and National Cholesterol Education Program recommend 25% to 35% of daily calories from fat. These total fat intake recommendations are based on evidence that indicates consumption outside of these ranges is associated with a greater intake of energy and SFA (fat intake >35%) or greater intake in carbohydrate (fat intake <20%); higher intake of carbohydrate leads to increases in plasma triglyceride and reductions in highdensity lipoprotein (HDL) cholesterol levels. According to the National Health and Nutrition Examination Survey (NHANES) 2009-2010, 33% of calories in the diets of both women and men came from fat, which is near the recommended upper limit of 35%. It is important to note that individuals often eat more than their energy needs, and examining total fat intake as a percentage of calories might well reflect more fat in the diet than is recommended and necessary. Although total fat recommendations have been emphasized, for example, low-fat diet (<20%); moderate-fat diet (20% to 35%); or high-fat diet (>35%), the importance of individual fatty acids has been overlooked. Achieving intake of total fat within the recommended range (20% to 35%) is an important goal, but the quality of fat in the diet is equally important. Altering fat consumption, for example, the unsaturated/saturated fat balance, instead of reducing total fat might be more advantageous to health and chronicdisease risk reduction. In tissues, an increase in concentration of one fatty acid corresponds to the reduction of the same magnitude of another fatty acid. The displacement or replacement of the quality of fatty acid is important to consider. Recent recognition that individual fatty acids have differing effects on health, even within the conventional fat categories, has brought examination of these fatty acids into the forefront. Although this reductionist viewpoint allows for understanding specific fatty acid functions and is important in determining which fatty acids are best for health, examination of the foods containing these fatty acids is also important. Knowledge of the individual fatty acids in foods provides a JOURNAL OF THE ACAD foundation for the RDN to make whole food recommendations to their clients. The variety of fatty acids in common fats and oils is provided in Table 1. Additional information on individual fatty acids in foods can be found at the US Department of Agriculture’s Nutrient Database (http://ndb.nal.usda. gov). DIFFERING, WIDE-RANGING IMPACTS ON HEALTH The structure of each fatty acid diff