Dietary fiber has been recommended for its possible benefits in reducing heart disease by lowering blood cholesterol. How is fiber thought to play its role in lowering blood cholesterol?

Correct Answer: B

Rationale: The correct answer is B. Viscous (soluble) fiber binds with bile acids in the intestine, which are then excreted. The liver must use cholesterol to make more bile acids, thereby lowering blood cholesterol levels. Choice A is incorrect as insoluble fiber does not bind with cholesterol in the large intestine. Choice C is incorrect as soluble fiber does not directly bind with cholesterol in the blood. Choice D is incorrect as insoluble fiber does not convert to bile in the large intestine to bind with cholesterol.

Correct Answer: B

Rationale: The correct answer is B: vitamin D and vitamin B12. Vegans may need to supplement vitamin D and B12 as these nutrients are mainly found in animal products. While choices A, C, and D are essential vitamins, they are not typically lacking in a vegan diet. Vitamin C can be obtained from various plant sources, vitamin A can be derived from beta-carotene in plants, and vitamin E and K are also found in plant-based foods. Niacin, although important, can be sourced from plant-based sources and is not a common deficiency in vegan diets.

Correct Answer: C

Rationale: A healthy body fat percentage for women typically ranges between 21% and 33%, with 25% being an average healthy body fat percentage. Choice A (5%) is too low for a healthy body fat percentage and is more in line with essential body fat levels. Choice B (15%) is also lower than the typical range for a healthy body fat percentage. Choice D (35%) is too high and would be considered high body fat for women.

Correct Answer: C

Rationale: The correct answer is C: Fats. A ketogenic diet is characterized by high fat intake, moderate protein intake, and very low carbohydrate intake. This diet aims to shift the body's metabolism to use fat as the primary source of energy instead of carbohydrates. Increasing fat intake while reducing carbohydrates is essential for achieving and maintaining a state of ketosis. Therefore, choices A, B, and D are incorrect as they do not align with the macronutrient adjustments required for a ketogenic diet.

Correct Answer: C

Rationale: The primary function of antioxidants in the diet is to neutralize free radicals. Free radicals can cause cellular damage, leading to various chronic diseases. Antioxidants help combat this oxidative stress by neutralizing free radicals. Choices A, B, and D are incorrect because antioxidants do not provide energy, support muscle growth, or increase blood sugar; their main role is in combating oxidative stress.