DH 209 Nutrition Exam

Correct Answer:

C. Total kilocalories

Explanation of the Correct Answer:

Total kilocalories (calories) consumed is the primary factor that determines body weight gain. When the body takes in more calories than it burns, the excess energy is stored as fat, leading to weight gain. Regardless of whether those calories come from carbohydrates, proteins, or fats, it is the total number of calories consumed versus expended that primarily affects weight gain. Consistently consuming more kilocalories than the body needs results in an increase in body fat.

Why the Other Options Are Incorrect:

A. Carbohydrate intake

While carbohydrates do contribute to total caloric intake, it is not just carbohydrates alone that lead to an increase in body weight. Weight gain occurs when there is an excess of total calories, not just carbohydrates.

B. Protein intake

Protein is essential for muscle repair and growth, but, like carbohydrates, it only contributes to weight gain when consumed in excess of the body's caloric needs. Protein alone does not directly lead to significant weight gain unless it contributes to an overall caloric surplus.

D. Fat intake

While fat is calorie-dense and can contribute to an increase in body weight, it is the total caloric intake that ultimately determines weight gain, not fat alone. Excessive fat intake can contribute to an increase in total calories, but it is the surplus of total kilocalories that leads to weight gain.

Summary:

The greatest effect on an increase in body weight is the total number of kilocalories consumed. This is the key factor in weight gain, regardless of whether the calories come from carbohydrates, proteins, or fats.

Correct Answer:

B. Cheese cubes

Explanation of the Correct Answer:

Cheese cubes are an excellent choice to reduce the risk of dental caries. Cheese contains calcium, phosphates, and casein, which help to neutralize acids in the mouth and remineralize tooth enamel. Cheese also stimulates saliva production, which helps to wash away food particles and neutralize harmful acids that can lead to tooth decay. Additionally, cheese has a low sugar content and does not contribute to plaque formation, making it a caries-preventive snack.

Why the Other Options Are Incorrect:

A. Caramel candy:

Caramel candy is high in sugar and sticky, which means it can cling to the teeth for longer periods of time, providing a food source for harmful bacteria in the mouth. These bacteria produce acids that lead to the demineralization of enamel and increase the risk of dental caries.

C. Peanut butter and crackers:

While peanut butter is a relatively healthy snack with healthy fats and protein, crackers are typically high in refined carbohydrates, which can break down into sugars in the mouth. These sugars can contribute to plaque formation and cavities. Also, peanut butter, while nutrient-dense, is sticky and can adhere to the teeth, prolonging the sugar's contact with the enamel, though it's a better choice than highly sugary snacks.

D. Raisins:

Raisins, although they are a natural source of fiber and nutrients, are dried fruit and contain high amounts of natural sugars. They are also sticky, meaning they can adhere to the teeth for longer periods, potentially increasing the risk of tooth decay. The sugar content in raisins can feed bacteria in the mouth, leading to acid production and increased risk of cavities.

Correct Answer: C. The body cannot store large amounts of fat soluble vitamins

Explanation of the Correct Answer:

C is correct because it is false that the body cannot store large amounts of fat-soluble vitamins. In fact, fat-soluble vitamins (A, D, E, and K) are stored in the body's fatty tissues and the liver. Unlike water-soluble vitamins, which are excreted easily, fat-soluble vitamins can accumulate over time, which can sometimes lead to toxicity if consumed in excessive amounts.

Why the Other Options are Incorrect:

A. They are necessary for cellular reactions

This is true. Fat-soluble vitamins are essential for various biological and cellular reactions. For example, vitamin A is important for vision and cellular differentiation, vitamin D for calcium absorption and bone health, vitamin E for antioxidant protection, and vitamin K for blood clotting.

B. They are organic substances

This is true. Fat-soluble vitamins are organic compounds, meaning they contain carbon and are derived from living organisms. Their organic nature is crucial for their function in metabolic processes.

D. Vitamin K is a fat soluble vitamin

This is true. Vitamin K is indeed a fat-soluble vitamin and plays a critical role in blood clotting and bone metabolism.

Summary:

The statement that the body cannot store large amounts of fat-soluble vitamins is false, making C the correct answer. Fat-soluble vitamins are organic substances essential for cellular reactions, and vitamin K is one of them. Unlike water-soluble vitamins, fat-soluble vitamins are stored in significant amounts in the body's fat tissues and liver.

Correct Answer:

D. Coconut oil

Explanation of the Correct Answer:

Coconut oil is known for being the most saturated fat among the options listed. About 90% of the fat in coconut oil is saturated. This high level of saturated fat content makes coconut oil solid at room temperature, similar to other highly saturated fats like butter or lard. Despite its high saturated fat content, coconut oil is often touted for containing medium-chain triglycerides (MCTs), which some believe may have health benefits, but it is still considered high in saturated fat overall.

Why the Other Options Are Incorrect:

A. Soybean oil

Soybean oil is primarily composed of polyunsaturated fats, with only about 14% of its fat content being saturated. It is often used as a healthier cooking oil due to its lower saturated fat content and higher amounts of omega-3 fatty acids.

B. Olive oil

Olive oil is considered a monounsaturated fat with about 14-15% saturated fat. It is praised for its health benefits, particularly for heart health, and is a primary fat source in the Mediterranean diet. The majority of the fat in olive oil is oleic acid, a monounsaturated fat known to be beneficial for reducing LDL (bad) cholesterol.

C. Canola oil

Canola oil is mostly composed of monounsaturated fats and polyunsaturated fats, with only about 7% saturated fat. It is considered a heart-healthy oil due to its high levels of omega-3 fatty acids (ALA) and low levels of saturated fat.

Correct Answer:

D. Cooking decreases the digestive process of some polysaccharides.

Explanation of the Correct Answer:

Cooking does not decrease the digestive process of polysaccharides. In fact, cooking often increases the digestibility of some polysaccharides. For example, cooking starches (a type of polysaccharide) can break down their structure, making them easier for digestive enzymes to act upon. So, this statement is incorrect because cooking usually aids in digestion, not hinders it.

Why the Other Options Are Correct:

A. They are complex carbohydrates.

This statement is true. Polysaccharides are indeed complex carbohydrates because they are made up of many (usually hundreds or thousands) monosaccharide units linked together.

B. Some polysaccharides have a role in energy storage.

This statement is true. Polysaccharides such as starch (in plants) and glycogen (in animals) are important for energy storage. These polysaccharides can be broken down into simpler sugars when the body needs energy.

C. They contain more than 10 monosaccharides.

This statement is true. Polysaccharides are defined as carbohydrates that consist of more than 10 monosaccharide units. Examples include starch, cellulose, and glycogen, which are all made up of many monosaccharide units.

Correct Answer: B. Chyme

Explanation of the Correct Answer:

B is correct because chyme is the semi-fluid mass that forms after food is ingested, mixed with gastric secretions, and churned in the stomach. It is the partially digested food that moves from the stomach into the small intestine for further digestion and nutrient absorption.

Why the Other Options are Incorrect:

A. Bile

This is incorrect because bile is a digestive fluid produced by the liver and stored in the gallbladder. It is released into the small intestine to aid in the digestion and absorption of fats, not a product of food digestion in the stomach.

C. Bolus

This is incorrect because bolus refers to the chewed food that is formed in the mouth and swallowed before it reaches the stomach. It is the mass of food that is ingested, but not yet mixed with gastric secretions.

D. Cholus

This is incorrect because cholus is not a recognized term in the context of digestion. The term that describes the semi-fluid mass formed in the stomach is chyme.

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:

C. Kilocalorie intake

Explanation of the Correct Answer:

Body weight is primarily influenced by the balance between the number of kilocalories (kcal) consumed and the number of kilocalories expended. Regardless of the macronutrient source—carbohydrates, fats, or proteins—an excess intake of kilocalories beyond the body’s energy requirements leads to weight gain. Kilocalories are the unit of measurement for energy in food, and when caloric intake consistently exceeds energy expenditure, the excess energy is stored in the body as fat, resulting in increased body weight. Therefore, it's the total caloric surplus—not just the type of nutrient—that has the most significant effect on body weight.

Why the Other Options Are Incorrect:

A. Carbohydrate intake

While carbohydrates can contribute to weight gain if consumed in excess, they are not inherently more fattening than other macronutrients. Carbohydrates provide 4 kcal per gram, and their effect on weight is dependent on the total caloric context. Moreover, not all carbs are equal—complex carbohydrates (e.g., whole grains) are less likely to contribute to fat gain than refined sugars when consumed in moderation.

B. Fat intake

Fats are more calorie-dense than carbohydrates and proteins, offering 9 kcal per gram. However, simply consuming more fat does not necessarily lead to weight gain unless it results in a calorie surplus. Some dietary fats, especially unsaturated fats, can be part of a healthy diet when portion-controlled. The key factor remains total kilocalories consumed, not fat intake alone.

D. Protein intake

Protein also provides 4 kcal per gram and plays a crucial role in muscle maintenance, enzyme function, and hormone production. High-protein diets can actually aid in weight management by promoting satiety and preserving lean muscle mass. Protein is less likely to be stored as fat because it has a higher thermic effect and supports metabolic functions. Therefore, protein alone is not a primary driver of weight gain unless part of an overall calorie surplus.

Correct Answer: False

Explanation of the Correct Answer:

The statement is false because fluoride incorporated into developing tooth enamel forms fluorapatite, which is actually more resistant to demineralization than hydroxyapatite (the naturally occurring mineral in enamel). Fluorapatite is more resistant to acids produced by bacteria in the mouth, making it less prone to decay and more resistant to the process of demineralization.

Why the Other Option is Incorrect:

True

This would be incorrect because fluorapatite (formed by fluoride incorporation into enamel) is more resistant to demineralization, not less. Fluoride helps in the remineralization process and strengthens the enamel, reducing the risk of tooth decay.