Designing a Diet
Diet Planning Principles:
- Five diet planning principles: adequacy, balance,
kcalorie control, moderation, and variety
- Adequacy – provide sufficient energy and nutrients
- Balance – consume a number of different foods in
appropriate proportion to each other
- Kcalorie control – energy balance between nutrient dense food versus energy dense food
- Nutrient and Energy density – large amount of nutrients
with a small amount of calories
- Nutrient density – ratio derived by dividing a food’s
contribution to nutrient needs by its contribution to energy need; when the
contribution to nutrient needs exceed its energy contribution, the food is
considered to have a favorable nutrient density
- example: soda versus nonfat milk
- Energy density – comparison of energy (kcal) content
of a food with the weight of the food; low energy-density foods in a meal
contributes to satiety without contributing many calories
- example: chocolate, bacon, potato chips, peanuts, fried foods
- Moderation – only a moderate consumption of foods not nutrient dense
- Variety – consume a variety of foods within and among
the food groups; bonus of variety is the inclusion of phytochemicals which may
reduce risk for certain disease:
|
Food |
Phytochemical(s) |
|
Allium vegetables (garlic,
onions, chives, leeks) |
Allyl sulfides |
|
Cruciferous vegetables
(broccoli, cauliflower, cabbage, Brussels sprouts,
kale, turnips, bok choy, kohlrabi) |
Indoles/glucosinolates,
Isothiocyanates/thiocyanates,
|
|
Solanaceous vegetables
(tomatoes, peppers) |
Lycopene |
|
Umbelliferous vegetables
(carrots, celery, cilantro,parsley, parsnips) |
Carotenoids,
Phthalides, |
|
Compositae plants
(artichoke) |
Silymarin |
|
Citrus fruits (oranges,
lemons, grapefruit)
|
Monoterpenes (limonene), Carotenoids, |
|
Other fruits (grapes,
berries, cherries, apples, cantaloupe, watermelon, pomegranate)
|
Ellagic acid ,
Phenols, Flavonoids (quercetin) |
|
Beans, grains, seeds
(soybeans, oats, barley, brown rice, whole wheat, flax seed)
|
Flavonoids (isoflavones),
Phytic acid,
Saponins,
Protease inhibitors |
|
Herbs, spices (ginger,
mint, rosemary, thyme, oregano, sage, basil, tumeric, caraway, fennel)
|
Gingerols,
Flavonoids,
Monoterpenes (limonene) |
|
Licorice root Green tea
|
Glycyrrhizin, Catechins |
Phytochemicals
and Function:
- Antioxidants - protect cells from oxidative
damage
- Polyphenols: lutein (yellow), lycopene (red), carotene (orange),
anthocyanin (blue)
- Flavanoids
- Isothiocynates
- Antithrombotic properties, lowers plasma
cholesterol levels, and may prevent cancer
- Hormonal action - imitate hormone function
- Isoflavones mimic estrogen
- Enzyme reactions - stimulate or inhibit enzyme reactions
- Protease inhibitors - stop viral replication
- Indoles - stimulate enzymes that regulate estrogen levels and affects
(thus preventing estrogen related cancers)
Question: Does your diet reflect the diet planning principles? Is your diet full of phytochemicals?
Question: How do we know if we are getting enough of other needed nutrients?
Dietary Reference Intakes (DRIs)
- The Dietary Reference Intakes
(DRIs) are a comprehensive set of nutrient reference values for healthy
populations that can be used for assessing and planning diets
- Background:
- They are established by
American scientists through a review process overseen by the Food and
Nutrition Board of the National Academy of Sciences
- 1941 until 1989, RDAs were established and used to
evaluate and plan menus that would meet the nutrient requirements of groups
- The primary goal was to prevent diseases caused by
nutrient deficiencies
- RDAs were not intended to evaluate the diets of
individuals
- Early 1990s Food and Nutrition Board revised RDAs
- Lead to the development of Dietary Reference Intakes (DRIs)
- Current Tables from National Academy of Sciences.
Institute of Medicine. Food and Nutrition Board:
DRI TABLES
- Five types of DRI reference values:
- Estimated Average Requirement (EAR)
- the average daily nutrient intake level estimated to meet the requirement
of half the healthy individuals in a particular life stage and gender group.
- EARs set by
- a functional marker such as an enzyme
- adjusting for the amount of each nutrient passes
through the digestive tract unabsorbed
- EARs can only be used to evaluate the adequacy of
diets of a group of people
- Recommended Dietary Allowance (RDA) -
the average daily nutrient intake level
sufficient to meet the nutrient requirement of nearly all (97 to 98 percent)
healthy individuals in a particular life stage and gender group
- Based on a multiple of EARs (RDA = EAR X 1.2)
- RDAs can only be set for nutrients if the Food and
Nutritional Board has enough information to determine an EAR
- Additional consideration in setting an RDA also can
be give to a nutrient’s ability to prevent chronic disease, rather just
prevent deficiency
- Adequate Intake (AI) - a
recommended average daily nutrient intake level based on observed or
experimentally determined approximations or estimates of nutrient intake by
a group (or groups) of apparently healthy people that are assumed to be
adequate – used when an RDA cannot be determined
- AIs based on observed or experimentally determined
estimates of the average nutrient intake that appears to maintain a
defined nutritional state in a certain population
- AIs have been set for two B vitamins, choline,
vitamin D, and minerals such as calcium and fluoride
- Estimated Energy Requirements (EER) - the
average need for various age groups and genders
- used to promote weight maintenance
- Tolerable Upper Intake Level (UL) -
the highest average daily nutrient intake level
likely to pose no risk of adverse health effects to almost all individuals
in the general population. As intake increases above the UL, the potential
risk of adverse effects increases.
- Upper level for most nutrients is based on the
combined intake of food, water, supplements, and fortified foods
- Exceptions: magnesium and zinc – Uls for these refer
only to nonfood sources
- New dietary reference values are used to not only
prevent nutrient deficiencies, but also reduce the risk of chronic diseases
- DRIs for various nutrients under study and reports have
been and will be submitted over years

Question:
if the public is not aware of the DRIs needed to maintain their health,
then what guidelines exist to help them make food choices?
Daily Values
- DRIs not use in food labeling because they are age and
gender specific
- New dietary reference value - Daily Values
- Developed by FDA in response to Nutrition Labeling and
Education Act of 1990
- DVs are not recommended intakes yet gives a person
perspective of the overall daily dietary needs
- 2,000 calories has been established as the reference for
calculating percent Daily Values
- DVs are based on two sets of dietary standards:
·
Reference Daily Intakes (RDIs) – for minerals and vitamins
o
Uses highest RDA values set in 1968
·
Daily Reference Values (DRVs) – for protein and dietary components
that have no RDA or other nutrient standard (fat, saturated fat, cholesterol,
carbohydrate, dietary fiber, sodium, and potassium)
o
Whatever the calorie level, DRVs for the energy-producing
nutrients are always calculated as follows:
§
fat based on 30 percent of calories
§
saturated fat based on 10 percent of calories
§
carbohydrate based on 60 percent of calories
§
protein based on 10 percent of calories. (The DRV for protein
applies only to adults and children over 4 - RDIs for protein for special groups
have been established.)
§
fiber based on 11.5 g of fiber per 1,000 calories.
o
The DRVs for cholesterol, sodium and potassium, which do not
contribute calories, remain the same whatever the calorie level
Food Choices - USDA
- USDA developed a comprehensive resource to
inform the general public about nutrients, food choices, exercise, and
overal health planing: ChooseMyPlate
- Emphasizes personalization, gradual improvement,
physical activity, variety, proportionality, and moderation - therefore
incorporates dietary planning principles
Questions:
What is the driving force that initiated the development of this
resource? Realistically speaking, how many people and what types of
people access such a resource?
Food Labels
- Information take from the FDA webpage: FOOD Labeling Guidelines
- Nutrition Labeling and Education Act of 1990 (NLEA) -
requires nutrition labeling for most foods (except meat and poultry) and
authorizes the use of nutrient content claims and appropriate FDA-approved
health claims
- Components found on a food label (Note: Bold items are
mandatory!)
- Total calories, calories
from fat, calories from saturated fat, total fat,
saturated fat, polyunsaturated fat, monounsaturated fat,
cholesterol, sodium,
potassium, total carbohydrate,
dietary fiber, soluble fiber, insoluble fiber,
sugars, sugar alcohol (for example, the
sugar substitutes xylitol, mannitol and sorbitol), other carbohydrate (the
difference between total carbohydrate and the sum of dietary fiber, sugars,
and sugar alcohol if declared), protein,
vitamin A, percent of vitamin A present as
beta-carotene, vitamin C,
calcium, iron, other essential
vitamins and minerals
- Panel format
- Serving size
- Servings per container
- Amounts per serving
- Calories/Calories from fat
- Total fat/Saturated fat
- Cholesterol
- Sodium
- Total Carbohydrate/Dietary fibers/Sugars
- Protein
- Vitamin A
- Vitamin C
- Calcium
- Iron
- Daily Values
- Nutrient content claims:
| Free |
This term means that a product contains no amount
of, or only trivial or "physiologically inconsequential" amounts of, one or
more of these components: fat, saturated fat, cholesterol, sodium, sugars, and
calories. For example, "calorie-free" means fewer than 5 calories per serving,
and "sugar-free" and "fat-free" both mean less than 0.5 g per serving.
Synonyms for "free" include "without," "no" and "zero." A synonym for fat-free
milk is "skim". |
| Low |
This term can be used on foods that can be eaten
frequently without exceeding dietary guidelines for one or more of these
components: fat, saturated fat, cholesterol, sodium, and calories. Thus,
descriptors are defined as follows:
- low-fat: 3 g or less per serving
- low-saturated fat: 1 g or less per serving
- low-sodium: 140 mg or less per serving
- very low sodium: 35 mg or less per serving
- low-cholesterol: 20 mg or less and 2 g or less of
saturated fat per serving
- low-calorie: 40 calories or less per serving.
Synonyms for low include "little," "few," "low source of," and "contains a
small amount of." |
| Lean |
These terms can be used to describe the fat content
of meat, poultry, seafood, and game meats.
- lean: less than 10 g fat, 4.5 g or less saturated
fat, and less than 95 mg cholesterol per serving and per 100 g.
- extra lean: less than 5 g fat, less than 2 g
saturated fat, and less than 95 mg cholesterol per serving and per 100 g.
|
| High |
This term can be used if the food contains 20
percent or more of the Daily Value for a particular nutrient in a
serving. |
| Good source |
This term means that one serving of a food contains
10 to 19 percent of the Daily Value for a particular nutrient. |
| Reduced |
This term means that a nutritionally altered product
contains at least 25 percent less of a nutrient or of calories than
the regular, or reference, product. However, a reduced claim can't
be made on a product if its reference food already meets the
requirement for a "low" claim. |
| Less |
This term means that a food, whether altered or not,
contains 25 percent less of a nutrient or of calories than the
reference food. For example, pretzels that have 25 percent less fat
than potato chips could carry a "less" claim. "Fewer" is an
acceptable synonym. |
| Light |
This descriptor can mean two things:
- First, that a nutritionally altered product contains one-third fewer
calories or half the fat of the reference food. If the food derives 50
percent or more of its calories from fat, the reduction must be 50 percent
of the fat.
- Second, that the sodium content of a low-calorie, low-fat food has
been reduced by 50 percent. In addition, "light in sodium" may be used on
food in which the sodium content has been reduced by at least 50 percent.
|
| Healthy |
A "healthy" food must be low in fat and saturated
fat and contain limited amounts of cholesterol and sodium. In
addition, if it' s a single-item food, it must provide at least 10
percent of one or more of vitamins A or C, iron, calcium, protein,
or fiber. Exempt from this "10-percent" rule are certain raw, canned
and frozen fruits and vegetables and certain cereal-grain products.
These foods can be labeled "healthy," if they do not contain
ingredients that change the nutritional profile, and, in the case of
enriched grain products, conform to standards of identity, which
call for certain required ingredients. If it's a meal-type product,
such as frozen entrees and multi-course frozen dinners, it must
provide 10 percent of two or three of these vitamins or minerals or
of protein or fiber, in addition to meeting the other criteria. The
sodium content cannot exceed 360 mg per serving for individual foods
and 480 mg per serving for meal-type products |
| Organic |
Foods in which do not use chemical fertilizers or
pesticides, genetic engineering, sewage sludge, antibiotics, or
irradiation in their production |