The Dietary Guidelines for Americans are the federal statement of
dietary guidance policy. The small bulletin presenting the guidelines
contains practical advice for healthy people about what constitutes a
healthful diet and how such a diet is important to health.
The Dietary Guidelines published by the USDA and Human Services
recommend that people maintain desirable weight, limit intake of fat
and cholesterol, and consume adequate amounts of starch and fiber.
Although these guidelines are developed by the US Department of
Agriculture and the Department of Health and Human Services for healthy
Americans, they have received the consensus by most authorities, and
can be used by *healthy people throughout the world.
*Healthy refers to people who do not suffer from
malnutrition or any other condition that requires a change in dietary
guidelines or nutrient allowances.
The 1990 Dietary Guidelines for Americans.
- Eat a variety of foods.
- Maintain healthy weight.
- Choose a diet low in fat, saturated fat, and cholesterol.
- Choose a diet with plenty of vegetables, fruits, and
- Use sugars only in moderation.
- Use salt and sodium only in moderation.
- If you drink alcoholic beverages, do so in moderation.
People should focus on their total diet in a more positive way,
especially with respect to fat and cholesterol. Most people following a
Western type diet are consuming far too much fat and cholesterol, and
not enough carbohydrate and fiber.
The easy way to overcome this problem is to eat moderate amounts of
foods from all the different food groups, and avoid dietary extremes
that include an excess of fatty foods, cholesterol, or sugars.
Eat a Variety of Foods:
All foods that supply calories and essential nutrients, potentially,
can be included in an adequate diet. In some cases, certain groups of
people (eg. pregnant women, vegetarians) should eat foods to obtain a
greater amount of a particular nutrient (eg. calcium-rich foods,
iron-rich foods). But, when choosing a greater variety of foods from
the different food groups, choose low-calorie foods, especially for
elderly persons and persons who are sedentary or trying to loose weight.
No single food can supply all the nutrients in the amounts you need.
To make sure you eat all the nutrients and other substances needed for
health, choose the recommended number of servings from each of the food
groups displayed in the Food Guide Pyramid.
Maintain Healthy Weight:
A healthy weight is the weight a person should be to live a healthy
life, and reduce the chances of conditions that are associated with
either obesity or malnutrition caused from hunger and starvation. "Too
lean" is a health problem often found in young women, too easily
influenced by the peer pressure of modern living. They strive to loose
weight even when they are under-weight.
A healthy weight can be calculated by considering body mass index
and waist-to-hip ratio. If a person is over-weight, and this is not
caused by a weight-related disease, the importance of following one of
the many weight reduction strategies and the necessity to exercise and
increase the amount of energy expended, is paramount.
To maintain weight you must balance the energy in food with the
amount of energy your body uses. Physical activity is an important way
to use up food energy. To use up dietary energy spend more time being
physically active, like walking the dog, and less time being inactive,
like watching television.
Ratios of weight to height estimate total body mass rather than fat mass, but they correlate highly with the amount of body fat.
[Revicki, D.A. and Israel, R.G. Relationship between body mass indices
and measure of body adiposity. American Journal of Public Health
76:992-94, 1986] The most commonly used ratio is known as
Quetelet's index, or the BMI, and is usually defined as body weight in
kilograms divided by the square of the height in meters (wt/ht2).
Table 2.1 Body Mass Index Used to Define Desirable Weight and Overweight for "Ideal" Reference Populations
| Mean | Overweight | Severe Overweight | |||
| Men | Women | Men | Women | Men | Women |
| 22.0 | 21.5 | 26.4 | 25.8 | 30.8 | 30.1 |
A reasonable weight reduction program should have a goal of ? to 1
pound per week. Loosing more than 1 pound a week is not recommended,
nor should drugs or other extreme means of weight reduction be used (See chapter on Dietary Fads and Frauds).Extreme
approaches to weight loss, such as self induced vomiting or the use of
laxatives, amphetamines, or diuretics, are not appropriate and can be
dangerous to health.
The table that follows lists healthy weight ranges for adults.
| Height | Weight (in Pounds) |
| 4' 10" 4' 11" 5' 0" 5' 1" 5' 2" 5' 3" 5' 4" 5' 5" 5' 6" 5' 7" 5' 8" 5' 9" 5' 10 5' 11" 6' 0" 6' 1" 6' 2" 6' 3" 6' 4" 6' 5" 6' 6" | 91 - 119 94 - 124 97 - 128 101 - 132 104 - 137 107 - 141 111 - 146 114 - 150 118 - 155 121 - 160 125 - 164 129 - 169 132 - 174 136 - 179 140 - 184 144 - 189 148 - 195 152 - 200 156 - 205 160 - 211 164 - 216 |
The higher values in the weight range apply to people with more
muscle and bone. Weights above this range are less healthy for most
people.
Choose a Diet Low in Fat, Saturated Fat and Cholesterol:
As already stated, there is a need for people following a Western
Diet to reduce the amount of fat, saturated fat and cholesterol that
they consume. Only about 25 percent of calories should come from fats,
and no more than 10 percent from saturated fats.
Risk for heart disease is increased among people with elevated blood
cholesterol levels. It is important to get your blood cholesterol
checked regularly. If blood cholesterol is above 5.2 mmol/L, follow the
advice of health professionals about diet and if necessary medication.
Fat, whether from plant or animal sources, contains more than twice
the number of calories as an equal amount of carbohydrate or protein.
Each gram of fat contains 9 calories. Some foods and food groups are
higher in fat than others. This guideline emphasizes the continued
importance of choosing a diet with less total fat, saturated fat, and
cholesterol.
Choose a Diet with Plenty of Vegetables, Fruits and Grain Products:
Foods that provide complex carbohydrates, dietary fiber, and other
components are linked to good health, mainly by lowering the fat
content in the diet. This guideline is consistent with the scientific
evidence that supports the health benefits of diets with more complex
carbohydrates and a variety of fiber-rich foods.
Most of the calories in your diet should come from grain products,
fruits and vegetables.These include bread, cereals, pasta, rice and
potatoes. Dry beans are included in the meat group but can also count
as servings of vegetables. Plant foods are generally low in fats,
depending on how they are prepared and what is added to them.
Fiber is found only in plant foods. Eating a variety of
fiber-containing foods is important for proper bowel function and can
reduce the risk of chronic constipation, diverticular disease, heart
disease and some cancers.
Use Sugars in moderation:
Sugars include all simple carbohydrates, such as sucrose, glucose
and lactose, and foods containing them such as candies, honey, and
chocolate.
Sugars and foods containing them in large amounts supply energy but
are limited in nutrients. Furthermore, sugars and starches, which break
down in the mouth, can contribute to tooth decay. The importance of
fluoride and dental hygiene in the prevention of tooth decay is also
stressed.
Sugar substitutes do not provide significant calories and may be
used to reduce calorie intake. However, foods containing sugar
substitutes may not always be lower in calories than similar products
that do contain sugar. Unless you reduce the total calories you eat,
the use of sugar substitutes will not cause you to lose weight.
Use Salt and Sodium in Moderation:
Sodium plays an essential role in regulating fluids and blood
pressure. However many studies have shown that a high sodium intake is
associated with high blood pressure. Eating foods high in potassium
helps to counter the effects of high sodium consumption on blood
pressure.
Using less salt and sodium than is normally used will benefit those
people whose blood pressure goes up with salt intake. Hereditary
factors as well as excessive drinking have also been shown to be
related to high blood pressure. Adults are encouraged to get their
blood pressure checked and, if it is high, to consult a physician about
diet.
It is easy to reduce sodium intake by using less salt in cooking and
on the table, but when eating processed foods it is important to look
on the label for sodium substances, as these are used excessively in
many types of sauces and condiments.
If You Drink Alcoholic Beverages, Do So in Moderation:
Alcohol has no net benefit to health and is not an essential
nutrient in any way. If you can not avoid drinking, do so in
moderation. One or two drinks per day are not usually associated with
health risks.
Inflammation of the pancreas and damage to the heart and brain are
some of the complications of drinking. Studies have shown that alcohol
is linked to risks of heart attacks, hypertension, haemorrhagic stroke,
cirrhosis of the liver, inflammation of the pancreas, violence,
suicide, birth defects and overall mortality.
Table 2.2 A comparison of recent government dietary recommendations for some nutrients.
Surgeon General's Report on Nutrition and Health. | National Research Council's Diet and Health. |
| Fat and cholesterol | |
| Reduce consumption of fat (especially saturated fat) and cholesterol. | Reduce total fat intake to 30% or less. Reduce saturated fatty acid intake to less than 10% of total calories, and intake of cholesterol to less than 300 mg daily. |
| Energy and weight control | |
| Achieve and maintain a desirable body weight. To do so, choose a diet in which caloric intake is consistent with energy expenditure. | Balance food intake and physical activity to maintain appropriate body weight. |
| Complex carbohydrate and fiber | |
| Increase consumption of whole grain foods and cereal products, vegetables (including dried beans and peas), and fruits. | Everyday eat five or more servings of a combination of vegetables and fruits, especially green and yellow vegetables and citrus fruits. Increase intake of starches and other complex carbohydrates by eating six or more daily servings of a combination of breads, cereals, and legumes. |
| Sodium | |
| Reduce intake of sodium by choosing foods low in sodium and limiting the amount of salt added in food preparation and at the table. | Limit total daily intake of salt to 6 gm or less. Limit salt in cooking and avoid adding it to foods at the table. |
| Calcium | |
| Adolescent girls and adult women should increase consumption of foods high in calcium, including low-fat dairy products. | Maintain adequate calcium intake. |
Calorie Requirements
In addition to requiring a certain amount of nutrients, your body
also requires a certain amount of calories daily. Total energy
expenditure includes the energy expended in rest, in physical activity,
and as a result of thermogenisis. These components, in turn,
are affected by several variables, including age, sex, body size and
composition, genetic factors, energy intake, physiologic state (eg.
growth, pregnancy, lactation), coexisting pathological conditions, and
ambient temperature.
- Resting Metabolic Rate represents the minimum energy needs of the body, for day and night with no exercise or exposure to cold.
- Sedentary includes occupations that involve sitting most of the day, such as office work and studying.
- Light includes activities which involve standing most of the day, such as teaching or laboratory work.
- Moderate may include walking, gardening, and housework.
- Active includes dancing, skating, and manual labor such as farm or construction work.
Table 2.3 Daily calorie allowance.
| MEN | WOMEN | |
| Activity level | Calories required | |
| Resting Sedentary Light Moderate Active | 12 per lb. body weight 16 per lb. body weight 18 per lb. body weight 21 per lb. body weight 26 per lb. body weight | 13 per lb. body weight 14 per lb. body weight 16 per lb. body weight 18 per lb. body weight 22 per lb. body weight |
Using the chart you can determine the amount of calories you require
daily, depending on your activity level . For example a 130 pound male
waiter requires 2730 calories. (Moderate activity level 21 x 130 lb =
2730 Cal.)
The following table indicates the approximate number of calories used by the body during a half-hour of the activity.
Table 2.4 Energy expenditure.
| ACTIVITY | ENERGY(Kcal per ? hour) |
| Badminton Basketball Cleaning Cooking, active Cycling, moderate Disco Driving Gardening Golf Jogging Marathon running Sitting Skiing (Nordic) Sleeping Squash Studying Swimming Tennis Walking Watching Television | 220 400 95 110 150 250 75 150 170 300 495 45 540 30 325 50 300 250 160 45 |
Metabolism
The person who can eat and eat and never gain a pound probably does
not exist, according to a recent US Department of Agriculture study.
The study should help resolve two conflicting schools of thought on
whether a person's metabolism automatically gears up to prevent weight
gain when eating extra calories day after day. The findings show very
little change in metabolism.
For three weeks, seven men consumed 1000 kcal more each day than
they would normally eat. All of them gained weight, on average a ¼ lb
per day.
After the men stopped overeating, they dropped weight rapidly, even
though they were told not to diet. They unconsciously chose fewer
calories than they would normally eat, primarily by avoiding high-fat
foods.
This supports the hypothesis that successful body weight regulation
might be associated with body fat and carbohydrate levels rather than
by a single factor such as total energy level. The men had plenty of
fat reserves, so they selected less fat.
While it's not uncommon for a persons' caloric intake to vary 1000
kcal from day to day, it's not easy to eat an extra 1000 kcal day after
day. The men consumed all the extra food they were given.
A greater potential for error lies in incorrectly estimating the
number of calories needed to maintain weight. It is very difficult to
make an accurate estimate. If researchers underestimate, then some of
the "extra" calories they feed the subjects are not really extra, and
the subject does not gain weight. [Metabolism does not change to
prevent weight gain during overfeeding. JADA 90:1556. 1990]
