DH 209 Nutrition Exam

Correct Answer:

B. True

Explanation of the Correct Answer:

Saturated fatty acids can undergo partial hydrogenation to be converted into tub spread margarine. Hydrogenation is a process that adds hydrogen atoms to unsaturated fatty acids, which can convert them into more saturated forms. In partial hydrogenation, not all double bonds in the unsaturated fatty acids are converted to single bonds, which results in the formation of trans fats. This process is commonly used in the production of margarine, including tub spreads, to alter the consistency and extend shelf life, although the resulting trans fats are associated with increased health risks.

Why the Other Option Is Incorrect:

A. False

This statement is incorrect because partial hydrogenation is indeed used to convert unsaturated fatty acids into margarine, including tub spread margarine. While the process may not convert all unsaturated fats into fully saturated fats, it can lead to the creation of margarine-like spreads.

Summary:

Saturated fatty acids can undergo partial hydrogenation, a process that is used in the production of margarine, including tub spreads. The correct answer is B: True.

Correct Answer: D. Fiber contributes to constipation

Explanation of the Correct Answer:

D is correct because fiber does not contribute to constipation; in fact, it helps to prevent constipation. Fiber, particularly soluble fiber, absorbs water and forms a gel-like substance, which softens stool and promotes regular bowel movements. Insoluble fiber adds bulk to the stool, helping it pass more easily through the intestines. Therefore, fiber is actually beneficial in preventing constipation, not causing it.

Why the Other Options are Incorrect:

A. Fiber increases stool bulk

This is correct because fiber, especially insoluble fiber, adds bulk to stool by absorbing water and helping to move waste through the digestive system more efficiently.

B. Fiber increases muscle tone of digestive muscles

This is correct because fiber promotes regular bowel movements, which can help stimulate the digestive muscles (peristalsis) to work more effectively, increasing their muscle tone and overall function.

C. Fiber slows starch hydrolysis

This is correct because soluble fiber can slow the breakdown of starches into simple sugars by forming a gel-like substance, which can help regulate blood sugar levels and prevent rapid spikes in glucose levels.

Correct Answer:

B. First is false, second is true.

Explanation of the Correct Answer:

The first statement is false because basal metabolic rate (BMR) actually decreases with age, not increases. As individuals get older, there is a natural decline in muscle mass and physical activity, leading to a slower metabolism. This reduction in BMR means that older adults burn fewer calories at rest.

The second statement is true because, as a result of the decreased BMR, older adults do indeed require fewer calories. This reduction in caloric needs is why dietary guidelines suggest that older adults should lower their caloric intake to prevent weight gain and maintain overall health.

Why the Other Options Are Incorrect:

A. First is true, second is false.

This option is incorrect because the first statement is false—BMR decreases, not increases, with age. Therefore, both statements cannot be true.

C. Both are false.

This option is incorrect because the second statement is true; older adults do require fewer calories due to a slower metabolism.

D. Both statements are true.

This option is incorrect because the first statement is false—BMR decreases with age, not increases. Therefore, both statements cannot be true.

Summary:

Basal metabolic rate (BMR) decreases with age, so the first statement is false. As a result of this decrease, older adults need fewer calories, which makes the second statement true.

Correct Answer:

C. Both are true

Explanation of the Correct Answer:

First statement: "Harvesting, processing, and cooking food means nutrient losses are occurring."

This statement is true. Harvesting, processing, and cooking can cause the loss of some nutrients in food, particularly vitamins and minerals. For example, cooking can degrade certain vitamins like vitamin C and folate, while processing may remove fiber and other nutrients.

Second statement: "Fortified foods have nutrients added that were not present in the original product."

This statement is also true. Fortification refers to the process of adding vitamins, minerals, or other nutrients to a food product that doesn't naturally contain them or contains them in insufficient amounts. Common examples include adding vitamin D to milk or adding folic acid to breakfast cereals.

Why the Other Options Are Incorrect:

A. First is true, second false

This is incorrect because the second statement about fortified foods is true, not false.

B. Both are false

This is incorrect because both statements are actually true.

D. First is false, second true

This is incorrect because the first statement is true, not false.

Summary:

Both the first and second statements are correct. Harvesting, processing, and cooking food can result in nutrient losses, and fortified foods have added nutrients that were not originally present in the product.

Correct Answer: D. Before conception

Explanation of the Correct Answer:

The most ideal time to begin taking folate to prevent neural tube defects is before conception. Folate, or folic acid, should be taken at least one month before conception and throughout the first trimester of pregnancy. This is because neural tube defects, such as spina bifida, can occur very early in pregnancy, often before a woman even knows she is pregnant. Adequate folate intake during this time is crucial in reducing the risk of these birth defects.

Why the Other Options are Incorrect:

A. Upon completion of the first trimester

This is incorrect because neural tube defects occur very early in pregnancy, and waiting until the first trimester is complete would be too late to provide the protective benefits of folate.

B. Second trimester

This is incorrect because the second trimester is too late to prevent neural tube defects. The critical period for neural tube formation is in the first few weeks after conception, so folate supplementation is necessary before conception and during the early stages of pregnancy.

C. From 6-8 weeks of pregnancy

This is incorrect because while it’s important to continue folate intake during the pregnancy, starting at 6-8 weeks would be too late to prevent neural tube defects, as the critical window for neural tube development occurs earlier in the pregnancy.

Correct Answer:

A. Cheese

Explanation of the Correct Answer:

Cheese is considered to have cariostatic properties because it helps neutralize acids in the mouth, reduces the demineralization of tooth enamel, and can promote remineralization. The calcium and phosphate in cheese also support tooth enamel, while the casein protein in cheese forms a protective layer on the teeth. Additionally, the act of chewing cheese stimulates saliva production, which further helps to neutralize acids and wash away food particles.

Why the Other Options Are Incorrect:

B. Vegetables

While vegetables are beneficial for overall health, they do not specifically have cariostatic properties. They can help stimulate saliva production but lack the specific minerals and properties that cheese offers for dental protection.

C. Seafood

Seafood is nutritious and contains minerals like calcium and fluoride, but it does not have the same direct protective effects against tooth decay as cheese does. While certain seafoods contribute to oral health, they are not classified as cariostatic.

D. Eggs

Eggs are a good source of protein and vitamins but do not have significant cariostatic properties. Although they are nutritious, they do not have the specific qualities needed to prevent tooth decay in the same way cheese does.

Summary:

Cheese is the food with the most cariostatic properties because it helps neutralize acids, supports tooth enamel, and promotes remineralization. Vegetables, seafood, and eggs are nutritious but do not have the same direct protective effects against tooth decay.

Correct Answer:

B. Poor oral hygiene

Explanation of the Correct Answer:

Dehydration itself does not directly cause poor oral hygiene, which is typically related to individual behaviors such as infrequent brushing, inadequate flossing, or neglect of overall oral care. Dehydration can cause dry mouth (xerostomia), which might make it more difficult to clean the mouth properly, but the actual cause of poor oral hygiene is the lack of consistent, proper oral care.

Why the Other Options Are Incorrect:

A. Increased caries susceptibility

Dehydration can indeed lead to dry mouth, which reduces the protective effects of saliva. When saliva production is low, harmful bacteria can thrive, leading to an increased risk of cavities. Therefore, dehydration can contribute to increased caries susceptibility.

C. Loose fitting dentures

Dehydration can affect the fit of dentures by reducing the amount of saliva, which helps keep dentures in place. Without adequate moisture, the tissues in the mouth become drier, leading to potential issues with denture fit. Therefore, dehydration can contribute to loose-fitting dentures.

D. Fecal impaction

Dehydration can cause constipation by making the stool harder and more difficult to pass. If constipation becomes severe, it can lead to fecal impaction. Therefore, dehydration is a contributing factor to fecal impaction.

Summary:

Dehydration can lead to dry mouth, which contributes to increased caries susceptibility and issues with dentures, but it is not a direct cause of poor oral hygiene, which is more related to a lack of regular oral care. Additionally, dehydration can lead to constipation and fecal impaction.

Correct Answer: B. Avoid eating for 2 hours prior to the dental appointment

Explanation of the Correct Answer:

Avoiding food intake for 2 hours prior to the dental appointment is recommended for patients with gastroesophageal reflux disease (GERD) because eating can stimulate acid production and increase the risk of acid reflux episodes during the appointment. Lying back in the dental chair can exacerbate reflux symptoms if the stomach is full, leading to discomfort, aspiration risk, or even erosion of the teeth from acid exposure. By avoiding food before the appointment, the patient minimizes these risks, ensuring greater comfort and reducing harm to oral structures.

Why the Other Options are Incorrect:

A. Brush their teeth immediately after a GERD acid exposure

This is incorrect. Brushing immediately after acid exposure can actually damage the enamel further. Acid weakens enamel, and brushing right afterward can erode it more severely. Instead, patients should be instructed to rinse with water or a fluoride mouthwash and wait at least 30 minutes before brushing to allow the enamel to remineralize and harden.

C. Drink orange juice before the dental appointment

This is incorrect. Orange juice is highly acidic and can worsen GERD symptoms and further expose teeth to acid, increasing the risk of erosion. Consuming acidic beverages before an appointment can promote reflux, cause discomfort, and harm oral health.

D. Enjoy spicy foods

This is incorrect. Spicy foods are known GERD triggers. They can relax the lower esophageal sphincter (LES), promote acid reflux, and worsen GERD symptoms. Patients with GERD are typically advised to avoid spicy foods to prevent flare-ups and related oral or gastrointestinal discomfort.

Summary:

The dental hygienist should advise the patient with GERD to avoid eating for at least 2 hours before the dental appointment to reduce the risk of reflux and protect both the patient's comfort and oral health. Immediate brushing after acid exposure, consuming acidic beverages like orange juice, and eating spicy foods are inappropriate recommendations because they can exacerbate GERD symptoms and cause further oral and esophageal damage.

Correct Answer:

A. Both statements are true.

Explanation of the Correct Answer:

The first statement is true because frequent intake of fermentable carbohydrates (such as sugars) promotes the growth of acid-producing bacteria in the mouth. These bacteria metabolize the sugars and produce acids, which lower the pH of plaque, making it more acidic. Acidic environments increase the risk of dental caries (tooth decay).

The second statement is also true. When the salivary pH drops to less than 7.5, it creates an environment conducive to demineralization of tooth enamel. This makes the carbohydrates cariogenic, meaning they can contribute to the formation of cavities. A pH lower than 7.5 is an indication that the acidic conditions in the mouth are promoting tooth decay.

Why the Other Options Are Incorrect:

B. Both statements are false:

This option is incorrect because both statements are true. Frequent carbohydrate intake does lower plaque pH, and a pH below 7.5 is indeed considered cariogenic for the teeth.

C. The first statement is false; the second is true:

This option is incorrect because the first statement is true. The frequency of fermentable carbohydrate intake does lower plaque pH, contributing to tooth decay.

D. The first statement is true; the second is false:

This option is incorrect because the second statement is also true. A drop in salivary pH to below 7.5 does make carbohydrates cariogenic.