AY Honors/Nutrition/Answer Key
Nutrition
Skill Level 1
1. Describe the food pyramid guide. List the number of servings required from each group per day. Why is it important to eat a balanced diet?
The food pyramid guide is updated and published by the United States Department of Agriculture (USDA). The 2005 version is shown here:
With the updated version, the USDA did away with "number of servings" criteria, and replaced it with a web-based tool that features individualized plans and statistics. The tool can be found at mypyramidtracker.gov. Other improvements to the pyramid include the replacement of "serving size" with the more objective "cups."
2. Explain the difference between the following:
The prefix lacto means milk, and can be found in words such as lactose (a chemical found in milk).
The prefix ovo means egg, and can be found in words such as oval (which means egg-shaped).
These prefixes are used to describe the exceptions to a vegetarian diet as follows:
a. Lacto-ovo vegetarian
A lacto-ovo vegetarian is a person who eats no animal products (such as meat) except for milk (and milk products such as cheese, ice cream, and yogurt), and eggs.
b. Ovo vegetarian
An ovo vegetarian is a person who eats no animal products (not meat and not milk) except for eggs.
c. Vegan vegetarian
A vegan is a vegetarian who eats no animal products at all.
4. What is another name for Vitamin B1 and B2?
Vitamin B1 is also known as thiamine. Beriberi is disease cause by a vitamin B1 deficiency.
Vitamin B2 is also known as riboflavin. It is required for red blood cell formation.
5. List at least three significant food sources of the following nutrients:
- a. Vitamin C: Citrus fruits (lime, lemon, orange, grapefruit), tomatoes, and potatoes are good common sources of vitamin C. Other foods that are good sources of vitamin C include papaya, broccoli, brussels sprouts, black currants, strawberries, cauliflower, spinach, cantaloupe, and kiwifruit. Also, cranberries and red peppers are good sources of the vitamin.
- b. Vitamin A: Milk and eggs are both animal sources of vitamin A. Carrots and spinach are both good plant sources of vitamin A.
- c. Vitamin B1: Good sources of vitamin B1 include whole grains (wheat, oats, rice, etc), apricots, pineapples, legumes, turnip greens, and pistacio nuts.
- d. Vitamin B2: Milk, cheese, leafy green vegetables, liver, yeast, almonds and mature soybeans are good sources of Vitamin B2, but exposure to light will destroy the riboflavin in these natural sources.
- e. Iron: Good sources of dietary iron include meat, fish, poultry, lentils, beans, leaf vegetables, tofu, chickpeas, black-eyed pea, strawberries and farina.
- f. Calcium: Dairy products, such as milk and cheese, are a well known source of calcium. However, some individuals are allergic to dairy and even more people, particularily those of non-European descent, are lactose-intolerant, leaving them unable to consume dairy. Fortunately, many other good sources of calcium exist. This includes nuts and seeds (like almonds and sesame), beans; whole wheat; collard greens; okra; rutabaga; broccoli; and fortified products such as orange juice and bread.
6. Why is it important to drink plenty of water every day? How much water should you drink every day?
7. Name three common diseases that can be controlled by diet.
8. What is the difference between whole wheat flour and white flour, and which one has the higher nutritive value?
The two biggest differences between white bread and whole wheat are the processing and the nutritional value. Whole wheat flour has the higher nutritive value.
Flour is made from wheat berries. The wheat berry is made up of the bran, the germ and the endosperm. All parts are filled with nutrients and are used in whole wheat flour.
White bread on the other hand, uses only the endosperm - the starchy inner layer. There are a total of 30 nutrients present in whole wheat bread that are missing in white bread. The nutritional difference is immense and has measurable impact on our health.
The fiber content of whole wheat bread has several health benefits.
Fiber helps the digestive system. It also creates a 'full' sensation and thus can help with weight control. Research has been conducted by Harvard and other organizations that shows men and women who eat high-fiber foods are less likely to have heart attacks and strokes as compared to those who don't.
There is also an increased risk of diabetes in children who eat refined white flour - a risk that has been proven by the increase in cases of childhood diabetes.
9. What does RDA stand for? What does it mean?
Recommended Dietary Allowance (RDA) is the daily dietary intake level of a nutrient that is considered sufficient to meet the requirements of nearly all (97-98%) healthy individuals in each life-stage and gender group. The RDAs are established by the Food and Nutrition Board of the (US) National Academy of Sciences.
10. Why is it important not to take excessive amounts of some vitamins and minerals?
Fat-soluble vitamins may be stored in the body and can cause toxicity when taken in excess. Water-soluble vitamins are not stored in the body, with the exception of Vitamin B12, which is stored in the liver.
Some of the most common causes of poisoning are vitamins A, B3 and B6. Conversely, certain vitamins do not produce toxicity in excess levels: vitamin C has been used in clinical trials in dosages over 100,000 mg — over 1000 times the daily recommended intake — without ill effects.
Excess doses of mineral supplements can also lead to poisoning. Either or both of vitamin poisoning and mineral supplement poisoning can occur due to excessive intake of multivitamin supplements.
