Correct Answer: C

Rationale: Low income is a significant factor contributing to marginal nutritional status due to limited access to nutritious food. While dependence on caffeine or acute illness can impact health, they are not as directly linked to marginal nutrition as low income. The size of the family unit may affect food distribution within the household but is not as directly related to marginal nutritional status as low income.

Correct Answer: B

Rationale: The correct answer is B: the unhealthy American public. The 2010 Dietary Guidelines primarily aimed to address the unhealthy eating habits prevalent in the American population. Choice A is incorrect as the focus was not solely on generally healthy segments of the population. Choice C is incorrect as the guidelines were not specifically tailored only for vulnerable population segments. Choice D is incorrect as the guidelines were more concerned with promoting healthy eating habits rather than ethnically diverse eating styles.

Correct Answer: C

Rationale: Protein provides 4 kcal per gram. Therefore, 15 grams of protein will provide 15 grams x 4 kcal/gram = 60 kcal. Choices A, B, and D are incorrect because they do not consider the caloric value of protein correctly.

Correct Answer: B

Rationale: Proteins are indeed macronutrients, along with carbohydrates and fats. Macronutrients are nutrients that provide energy and are required in large amounts by the body. Minerals and vitamins are considered micronutrients, as they are needed in smaller quantities. Enzymes, on the other hand, are not nutrients but rather biological molecules that act as catalysts in biochemical reactions.

Correct Answer: B

Rationale: Biochemistry is the correct answer because it focuses on understanding the chemical processes related to nutrition and how nutrients affect the body. Anatomy (choice A) primarily deals with the structure of organisms, not the chemical processes of nutrition. Physics (choice C) deals with energy and matter, not specifically related to nutrition. Pharmacology (choice D) focuses on drugs and their interactions with the body, not directly related to nutrition and its effects on health.