Correct Answer: A

Rationale: The correct answer is A: prevention and control of chronic diseases. In this century, nutritional recommendations have increasingly emphasized the importance of preventing and managing chronic diseases like obesity, diabetes, cardiovascular diseases, and cancer. Lifestyle factors such as diet play a significant role in the development of these conditions. Option B, improved sanitation and public health, although important for overall health, is not the primary focus of nutritional recommendations. Option C, prevention and control of infectious diseases, is also crucial but does not reflect the current major focus of nutritional recommendations. Option D, development of healthful foods using food technology, is a valid area of interest but is not the primary shift in focus observed in nutritional recommendations.

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: D

Rationale: The correct answer is D: 45% to 65%. Carbohydrates should contribute between 45% to 65% of the total daily caloric intake for healthy individuals to maintain a balanced diet. Choices A, B, and C are incorrect because they suggest lower ranges, which may not provide sufficient energy from carbohydrates for overall health and well-being.

Correct Answer: C

Rationale: The correct answer is C. Understanding serving sizes is crucial because most people have difficulty estimating the amount of food they eat. It helps individuals accurately track their intake, which is essential for maintaining a healthy diet and avoiding overeating. Choice A is incorrect because the question focuses on portion sizes rather than specific nutrients. Choice B is incorrect as it presents an unsupported claim about serving sizes decreasing. Choice D is incorrect as weighing food portions is not always necessary to check serving sizes; understanding standard serving sizes allows for a more practical approach to portion control.

Correct Answer: C

Rationale: Dietary guidelines are designed to assist individuals in making smart food choices by providing recommendations on what to eat to maintain good health. While portion sizes may be a part of these guidelines, they are not the primary focus. Designing a personal food plan involves individual preferences and needs, which may go beyond general guidelines. Avoiding excessive nutrient intakes is important, but dietary guidelines aim to provide balanced recommendations rather than just focusing on avoiding excess.