29 Ocak 2008 Salı

Diets of Americans

American eating habits more closely follow national dietary guidelines than they did a decade ago, but there's plenty of room for improvement.

There was a shift to a lower-fat, higher-carbohydrate diet between 1977-78 and 1989-90, according to surveys conducted by USDA's Human Nutrition Information Service. But the amount of fat in the average diet is still higher than recommended. And Americans are still not eating the amounts of fruits, vegetables, grains and low-fat dairy products that are recommended in the latest dietary guidance. For example, almost a quarter of the population ate no fruit in the 3 days of the 1989-90 survey period.

The most recent survey participants were asked to provide dietary data for three consecutive days, first in a personal interview and then by filling out forms. Estimates discussed here are averages for the 7,780 individuals who participated and are compared with data collected in a 1977-78 survey.

The results show a Nation that's eating more in conformance with the Food Guide Pyramid, which places bread, cereal, rice, and pasta at the base and fats, oils, and sweets at the tip, but we still have much to learn. The food intake results are grouped below as they're grouped in the Food Guide Pyramid.

Bread, Cereal, Rice, and Pasta Group

Americans are certainly eating more grains. The average intake of grain products increased from 213 grams in 1977-78 to 254 grams in 1989-90—a 19-percent increase.

Almost everyone ate at least one grain product over the survey period. There were practically no differences in total grain products eaten at different income levels. (Total grains include breads, cereals, pastas, cakes, cookies, pies, grain mixtures, etc.) Teenage boys ate the most total grain products, while women over 30 and young children ate the least. Men and women 20 to 29 and 40 to 49 years of age were the least likely to eat cereals and pastas, and generally ate the smallest amounts.

In 1989-90, males 6 to 39 and females 6 to 29 ate the largest amounts of grain mixtures—mixtures with a grain product as the main ingredient, such as pizza, tacos, or macaroni and cheese. Although the older age groups ate smaller amounts of grain mixtures than the younger groups, all groups ate more in 1989-90 than people the same age did a decade earlier.

Fruit Group

Americans ate about the same amount of fruit in 1989-90 as in 1977-78, but some people are eating little or no fruit. More than a fourth of the population ate no fruit and drank no fruit juice during the 3 consecutive days of record-keeping.

A larger proportion of low-income people (33 percent) ate no fruit than did high-income people (23 percent). Men 20 years old and over were more likely than women 20 and over to eat no fruit. In the low- income population, no fruit was eaten in 3 days by 39 percent of teenage boys and by 43 percent of men 20 years and older. More than half (52 percent) of the people who reported that they did not have enough to eat did not eat fruit over the 3 survey days.

Only 2 percent of high-income elderly women and 4 percent of middle-income elderly women ate or drank no fruit or fruit juices in the 3 days, compared with 19 percent of low-income elderly women. A higher proportion of low-income blacks (36 percent) than high-income blacks (25 percent) consumed no fruit or fruit juice.

Vegetable Group

The average daily intake of vegetables was slightly lower in 1989-90 than in 1977-78-179 grams versus 198 grams (a cup of lettuce weighs 55 grams and one medium raw tomato, 123 grams). These numbers do not include vegetables eaten as parts of mixtures, which frequently include vegetables.

Most individuals ate at least one vegetable over the 3-day survey period. Vegetable intakes in 1989-90 were lower for the low-income group (145 grams) than for the high-income group (197 grams).

For both sexes, total vegetable intake generally increased with age. A greater proportion of the vegetables eaten by younger than older people was white potatoes, including french fries and potato chips. For example, white potatoes accounted for 49 percent of the vegetables eaten by males age 12 to 19, but for only 25 percent of the vegetables eaten by males age 60 to 69. Overall, about 15 percent of the intake of white potatoes was french fries. The proportion of white potatoes eaten as french fries was highest among males under 30 and females under 20 years of age.

In dietary recommendations, legumes (dry beans and peas) are counted either as meat alternates or as vegetables. Only about 25 percent of individuals ate legumes over the 3-day period of the surveys.

Meat, Poultry, Fish, Beans, Eggs, and Nuts Group

Total intake of meat, poultry, and fish dropped slightly, from 204 grams in 1977-78 to 184 grams in 1989-90—a 10-percent decrease. In 1989-90, the amount of meat, poultry, and fish consumed was higher in the high-income group (198 grams) than in the low-income group (160 grams).

In 1977-78, red meats (beef, pork, lamb, veal, and organ meats) accounted for the largest share of the total consumption of meat, poultry, and fish; in 1989-90, mixtures made up the largest share. There was little change between the two survey periods in the consumption of poultry; fish and shellfish; and frankfurters, sausages, and luncheon meats.

Many foods are mixtures of two or more ingredients. For example, a sandwich is a mixture of bread and fillings. Mixtures reported as a single item (for example, a ham sandwich) are usually included as a single item in the food group of the major ingredient (in this case, ham). "Mixtures mainly meat, poultry, or fish" (meat mixtures) are defined as mixtures having meat, poultry, or fish as a main ingredient, such as beef potpie, chicken cacciatore, or tuna-noodle casserole.

In 1989-90, Americans ate more meat mixtures than in 1977-78; the amount of meat mixtures was up by about one-fifth—from 69 grams to 83 grams. The proportion of individuals who ate meat mixtures at least once in 3 days increased from 60 to 65 percent.

A lot of those mixtures come as hamburgers. About 17 percent of the survey respondents ate a hamburger (or cheeseburger or pizzaburger) on a bun at least once in 3 days in 1989-90; more boys and men 12 to 29 and girls 6 to 19 years old ate hamburgers than did people in other age groups. The percentage of individuals eating hamburgers was twice as high among blacks as among whites, was higher in the South than in other regions, and was higher in the middle- than in the low-or high-income groups.

About 41 percent of individuals ate eggs at least once in 3 days in 1989-90, down from 55 percent in 1977-78. In 1989-90, the proportions of individuals who reported eating eggs were highest among children 1 to 2 years old, men20 to 39 years old, men 60 and over, blacks, and low-income people.

Milk, Yogurt, and Cheese Group

In 1989-90, Americans drank about the same amount of total milk and milk products as they did in 1977-78. As a share of total milk and milk products, however, lowfat and skim milk went up while whole milk went down between the two surveys. Milk desserts and cheese stayed the same. "Other fluid milk," which includes milk not specified as to type, was a much larger share of the total in 1977-78 than in 1989-90; more people specified the fat content of their milk in the most recent survey, perhaps reflecting increased awareness of fat in the diet.

In 1989-90, children and teenagers drank the most fluid milk and men and women age 40 to 69 drank the least. Overall, 60 percent of the milk we drank was lowfat or skim, and older age groups generally drank larger proportions of their milk as lowfat or skim milk. The proportion of fluid milk intake that was lowfat or skim milk was much lower among blacks (23 percent) than among whites (65 percent). Low-income people (those with household incomes below 131 percent of the Federal poverty level) drank 37 percent of their milk as lowfat or skim, compared with 58 percent for middle-income people (those with incomes 131 percent to 300 percent of poverty) and 72 percent for high-income people (those with income over 300 percent of poverty).

In 1977-78, people drank nearly twice as much of both milk and coffee as they did of soft drinks; by 1989-90, the amounts of milk, coffee, and soft drinks were almost equal. While average milk and coffee consumption stayed about the same, soft drink consumption increased from 141 to 238 grams—an increase of 69 percent. Intake of low-calorie soft drinks more than tripled, from 20 grams in 1977-78 to 62 grams in 1989-90. A cup of milk weighs 245 grams; of black coffee, 240 grams; of soft drink, 248 grams. In 1989-90, men and women age 40 to 69 drank the most coffee. On the other hand, soft drinks were most popular with 12- to 49-yearolds. Overall, a little more than one-fourth of the soft drinks we drink are low-calorie. For women 50 to 69 years old, low-calorie soft drinks accounted for over half of total soft drink consumption. Low-income people and blacks drank less coffee, but more fruit drinks and ades than did people in the middle- and high-income groups and whites.

While some Americans are drinking lower-fat milk, many of them are drinking no milk at all—at least they did not during the 3 days covered by the survey. About a quarter of low-income and middle-income teenage girls did not drink milk in the 3 days. Only 3 percent in the highest income group drank no milk.

And elderly women at low and middle incomes were much less likely to drink milk than elderly women at the high-income level. Practically all children in the survey reported drinking milk.

Calcium is a current public health issue. Nearly all groups of teenagers and adults in the 1989-90 survey had calcium intakes below their Recommended Dietary Allowances (RDA), and the average calcium intake for women age 20 and over was 66 percent of the RDA. Milk and milk products are the major sources of calcium for Americans. However, intakes of carbonated soft drinks for teenagers and adults under 60 years of age were about equal to or higher than intakes of fluid milk.

The large increases in the share of milk intakes that were low-fat or skim and in the share of soft drinks that were low-calorie suggest that people are interested in limiting calories, fat, and sugar. Any of those interests could be satisfied by continuing to increase intakes of lowfat or skim milk and milk products, which would result in higher calcium intakes as well.

Fats, Oils, and Sweets Group

In 1989-90, total fat provided 35 percent of calories, and saturated fat provided 12 percent. Cholesterol intakes averaged 259 milligrams (mg).

The 1990 Dietary Guidelines for Americans recommend that individuals have a total fat intake of no more than 30 percent of calories and a saturated fat intake of less than 10 percent of calories. Many health authorities recommend a cholesterol intake of less than 300 mg daily.

The percentages of calories from total fat and saturated fat differ little by sex and age, by income, and by race. Cholesterol intakes are considerably higher for men than for women. Among men, average cholesterol intakes ranged from 296 mg for men age 70 and over to 365 mg for men 20 to 29 years old.

Americans got less energy from fat and more from carbohydrate in 1989-90 than in 1977-78. Factors contributing to the reduced percentage of energy from fat include changes in the food available, such as more lower-fat products and leaner meats; changes in food choices, such as the shift from whole to lowfat and skim milk; and the increased use of foods high in carbohydrate, such as grain products and sweetened beverages.

Energy and Nutrients

On average, the food eaten in the 3 days of the survey provided consumers with 1,763 calories per day. As expected, men eat more than women: The average food energy intake in 1989-90 was 2,119 calories for men 20 and over and 1,492 calories for women 20 and over. Energy intakes peaked at about 2,457 calories for males 12 to 29 years then declined progressively in older groups. Among females, energy intakes peaked at 1,688 calories for 6- to 11-year-olds then declined. For most age groups, calorie levels are slightly lower than they were in 1977-78.

The average energy intake in the low-income group was 1,610 calories, versus 1,773 calories in the middle-income group and 1,839 calories in the high-income group. The average energy intake was slightly lower for blacks (1,714 calories) than for whites (1,773 calories).

For nearly all age, income, and race groups, the reported energy levels are below the average energy allowances recommended in the 10th edition of the Recommended Dietary Allowances (RDA). However, there is some evidence that people in nutrition surveys underreport the food they eat, either by completely omitting food items or by underestimating the amount eaten. Also, the average energy allowances are designed for a light-to-moderate level of physical activity. It is possible that Americans' actual level of physical activity is lower than light-to-moderate.

Intakes of some nutrients are below the RDA. Average nutrient intakes for most groups exceed the RDA for protein, vitamin A, vitamin C, thiamin, riboflavin, niacin, folate, vitamin B-12, and phosphorus. For some nutrients—vitamin E, vitamin B-6, calcium, magnesium, iron, and zinc—intakes were below the RDA for many groups. In 1977-78, intakes of vitamin B-6, calcium, magnesium, and iron were below the 1980 RDA for many groups; vitamin E and zinc were not examined in the 1977-78 survey.

For those nutrients below the RDA, intakes were lower for women than for men age 20 to 29, as they were in nearly all age groups. For three nutrients—vitamin B-6, calcium, and zinc—average intakes were below the RDA regardless of income, but intakes were lower for low-income than for high-income individuals. Average calcium intake as a percentage of the RDA varied by race and was much lower for blacks (75 percent of RDA) than for whites (91 percent of RDA). Vitamin B-6 and zinc intakes were similar for blacks and whites, although both races had intakes below the RDA.

An average intake below the RDA does not necessarily mean that people in a group were malnourished. Individuals' nutrient requirements differ, and the RDA are set high enough to meet the requirements of nearly all healthy individuals. Thus, the RDA exceed the requirements of many individuals. However, the risk that some individuals have inadequate intakes increases as the average intake for the group falls further below the RDA.

More than one-fourth of the population consumed no fruit or fruit juice in 3 consecutive days in 1989-90. These individuals had average intakes of vitamins A and C that, when expressed as percentages of the RDA, were 38 to 70 percentage points below those of the population as a whole. Among people who consumed no fruit or fruit juice in 3 days, several age groups of women had intakes that were below RDA for vitamin A. For example, women 20 to 29 years who ate no fruit in 3 days had an average intake of vitamin A that was 74 percent of the RDA. Vitamin C intakes met the RDA for most groups of children, teenagers, and young men who ate no fruit in 3 days. However, men 70 and over had a vitamin C intake that was 69 percent of the RDA, and women 20 and over had vitamin C intakes that ranged from 67 to 81 percent of the RDA.

Individuals who consumed no fruit in 3 days and who also indicated they did not have enough food to eat had an average vitamin C intake that was 82 percent of the RDA. Individuals who ate no fruit in 3 days also had a higher percentage of calories from fat (37 percent) than did all individuals (35 percent).

Calcium intakes are below the RDA for many population groups; women age 20 and over, for example, have intakes that range from 66 to 81 percent of the RDA. Calcium intakes are even lower for the more than one-fourth of women age 20 and over who drank no fluid milk in 3 days. For these women, calcium intakes ranged from 45 to 54 percent of the RDA. Calcium intakes by men age 20 and over who drank no milk in 3 days ranged from 54 to 70 percent of the RDA. The calcium intake for teenage girls in the general population was 65 percent of the RDA; in contrast, teenage girls who drank no milk in 3 days

Hiç yorum yok: