12/02
Update
New Dietary Reference Intakes for Energy, Carbohydrate,
Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids
Prepared
by: Janice
Hermann, Ph.D., R.D./L.D.
Nutrition
Education Specialist
104
HES, Room 313
OCES,
(405)
744-6824
jrher@okstate.edu
Source: Food and Nutrition
Board,
IMPLICATIONS FOR COOPERATIVE EXTENSION. The
National Academy of Sciences released the latest report on the Dietary
Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids,
Cholesterol, Protein and Amino Acids. Tables on the Dietary Reference Intakes
for energy, carbohydrate, fiber, fat, fatty acids, and protein are available on
the Oklahoma Cooperative Extension Service Food and Nutrition web site at
www.fcs.okstate.edu/food/nutrition/basics/dri/.
New Dietary Reference Intakes for Energy, Carbohydrates,
Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
The Food and Nutrition
Board, is a unit of the
In the past,
recommended dietary allowances or RDAs have served as the benchmarks of
nutritional adequacy in the
The DRIs are designed
to meet the needs of individuals who are healthy and free of specific diseases or conditions that
may alter their daily nutritional requirements. It is expected that people
known to have specific conditions or chronic diseases will get nutritional
advice from their health professionals that is tailored to their special needs.
The Panel on
Macronutrients from the Food and Nutrition Board, recently released the latest
report on the Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat,
Fatty Acids, Cholesterol, Protein, and Amino Acids, collectively known as
New Dietary Reference Intakes for Energy,
Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids
(continued)
New Eating and Physical Activity Targets To
Reduce Chronic Disease Risk
macronutrients. This is the sixth in a series of Dietary
Reference Intake reports. To meet the
body's daily energy and nutritional needs while minimizing risk for chronic
disease, adults should get 45 percent to 65 percent of their calories from
carbohydrates, 20 percent to 35 percent from fat, and 10 percent to 35 percent
from protein, says the newest report on recommendations for healthy eating from
the National Academies'
Because carbohydrates,
fat, and protein all serve as energy sources and can substitute for one another
to some extent to meet caloric needs, the recommended ranges for consuming
these nutrients should be useful and flexible for dietary planning. Earlier
guidelines called for diets with 50 percent or more of carbohydrate and 30
percent or less of fat; protein intake recommendations are the same. The new
acceptable ranges for children are similar to those for adults, except that
infants and younger children need a slightly higher proportion of fat -- 25
percent to 40 percent of their caloric intake, said the panel that wrote the
report.
The panel established
ranges for fat, carbohydrates, and protein because they must be considered
together. Studies show that when people eat very low levels of fat combined
with very high levels of carbohydrates, high-density lipoprotein concentration,
or "good" cholesterol," decreases. Conversely, high-fat diets
can lead to obesity and its complications if caloric intake is increased as
well, which is often the case. We believe these ranges will help people make
healthy and more realistic choices based on their own food preferences.
The
report stresses the importance of balancing diet with physical activity,
recommending total calories to be consumed by individuals of given heights,
weights, and genders for each of four different levels of physical activity.
For example, a 30-year-old woman who is 5 feet 5 inches tall and weighs 111 to
150 pounds should consume between 1,800 and 2,000 calories daily if she lives a
sedentary lifestyle. However, if she is a very active person, her recommended
total caloric intake increases to 2,500 to 2,800 calories per day. If her
lifestyle fits the moderately active category as defined in the report, which
is the minimum level of activity to decrease risk of chronic disease, she
should eat between 2,200 and 2,500 calories daily. Using grams for the
recommended ranges of intake, she should consume 55 to 97 grams of fat and 285
to 375 grams of carbohydrates per day.
The new one-hour-a-day-total activity goal stems from studies
of how much energy is expended on average each day by individuals who maintain
a healthy weight. Energy expenditure is cumulative, including both
low-intensity activities of daily life, such as stair climbing and
housecleaning, and more vigorous exercise like swimming and cycling. Someone in
a largely sedentary occupation can achieve the new exercise goal by engaging in
a moderate-intensity activity, such as walking at 4 miles per hour, for a total
of 60 minutes every day, or engaging
in a high-intensity activity, such as jogging for 20 to 30 minutes four to
seven days per week.
Concern About
Added Sugars
Both children and
adults should consume at least 130 grams of carbohydrates each day, the report
says. However, this newly set RDA is based on the minimum amount of
carbohydrates needed to produce enough glucose for the brain to function, and
most people regularly consume far more.
The report suggests
that added sugars should comprise no
more than 25 percent of total calories
New Dietary Reference
Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein
and Amino Acids (continued)
consumed.
Distinguished from natural sugars, such as lactose found in milk and fructose
found in fruits, added sugars are those incorporated into foods and beverages
during production. Major sources include candy, soft drinks, fruit drinks, pastries, and other sweets. The
suggested maximum level stems from the evidence that people whose diets are
high in added sugars have lower intakes of essential nutrients.
Are All Fats Bad?
Fat is a major source
of energy for the body and aids in the absorption of essential vitamins. Some
foods that are major contributors of fat in the diet include butter, margarine,
vegetable oils, visible fat on meat and poultry, whole milk, egg yolks, and
nuts. High-fat diets usually mean increased intakes of saturated fat, which can
raise the amount of low-density lipoprotein and the level of "bad"
cholesterol in the bloodstream of some individuals and heightens their risk for
heart disease. Meats, baked goods, and full-fat dairy products are the main
sources of saturated fat in most diets. Because saturated fat and cholesterol
provide no known beneficial role in preventing chronic diseases, they are not
required at any level in the diet, the report says. Recognizing that completely
eliminating saturated fat and cholesterol from the typical diet in the
Monounsaturated and
polyunsaturated fatty acids, also present in fat, reduce blood cholesterol levels
and thus lower the risk of heart disease when they replace saturated fats in
the diet. People must get two types of polyunsaturated fatty acids, known as
alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6
fatty acid), from the foods they consume since neither is synthesized in the
body. A lack of either one will result in symptoms of deficiency, including
scaly skin and dermatitis, although these deficiencies are extremely rare in
the
Partially hydrogenated
vegetable oils, such as those used in many margarines and shortenings, contain
a particular form of unsaturated fat known as trans
fatty acids. Trans fatty acids have physical
properties generally resembling saturated fatty acids, and their presence tends
to harden oils. The report's findings and recommendations on trans
fatty acids were released in early July at the request of the Food and Drug
Administration as an important step in its process to determine whether trans
fat should be listed on nutrition labels. Often found in cookies, crackers,
dairy products, meats, and fast food, trans fatty
acids increase the risk of heart disease by boosting levels of bad cholesterol.
Because they are not essential and provide no known health benefit, there is no
safe level of trans fatty acids and people should eat as little of them as
possible while consuming a nutritionally adequate diet. Because trans fatty acids occur in so many types of food, an all-out
ban is impractical and would make it extremely difficult to get a nutritional
adequate diet, the panel added.
New Facts on Fiber
The report contains
the first recommended intake levels for fiber from the Food and Nutrition
Board. The fiber recommendations are based on studies that show an increased
risk for heart disease when diets low in
fiber are consumed. Although there is some evidence to suggest that fiber
in the diet may also help to prevent colon cancer and promote weight control,
the data are inconclusive at this point. The recommended daily intake for total
fiber for adults 50 years and younger is set at 38 grams for men and
New Dietary Reference
Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein
and Amino Acids (continued)
25 grams for women,
while for men and women over 50 it is 30 and 21 grams per day, respectively,
due to decreased consumption of food. The report also provides recommended
intakes for children and teenagers.
Many new food products
are marketed as containing fiber, but the lack of a uniform definition of fiber
for regulatory purposes casts doubts on the usefulness of some content claims. Therefore, the report provides a specific
definition of what should be called fiber in food. It defines "total
fiber" as the combination of "dietary" and
"functional" fiber. Dietary fiber is the edible, non-digestible
component of carbohydrates and lignin naturally found in plant food. Some foods
with dietary fiber include cereal bran, flaked corn cereal, sweet potatoes,
legumes, and onions. Functional fiber refers to those fiber sources that are shown to have similar health
benefits as dietary fiber, but are isolated or extracted from natural sources
or are synthetic. An example would be pectin extracted from citrus peel and
used as a gel that is the basis for jams and jellies. The definition of
functional fiber aims to exclude fiber-like products, whether extracted or
synthesized, that cannot be shown to have proven health benefits. It is hoped
that regulatory bodies in both the
Recommended Levels for Protein
The report establishes
age-based requirements for the first time for all nine of the essential amino
acids found in dietary protein. Values are included for pregnant women,
infants, and children based on their special needs. Using new data, the report reaffirms previously
established recommended levels of protein intake, which is 0.8 grams per
kilogram of body weight for adults. Recommended intake of protein during
pregnancy also is increased. Because
data on the potential for high-protein diets to produce chronic or other
diseases are often conflicting or inadequate, tolerable upper intake levels for
consumption could not be determined for protein or for the individual amino
acids. However, given the lack of data on over consumption for some of these
amino acids and protein, caution is warranted in consuming levels significantly
above those normally found in foods.
Tables on the Dietary Reference Intakes for
energy, carbohydrate, fiber, fat, fatty acids, and protein are available on the
Oklahoma Cooperative Extension Service Food and Nutrition web site at
www.fcs.okstate.edu/food/nutrition/basics/dri/. You can read the full text of
the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty
Acids, Cholesterol, Protein and Amino Acids at http://www.nap.edu/catalog/10490.html?onpi_topnews090402 for free.
Printed copies are also available for purchase from the National Academy
Press; tel. (202) 334-3313 or 1-800-624-6242 or on the Internet at www.nap.edu.