Why is fat important in the diet?

Correct Answer: C

Rationale: Fat is important in the diet because it provides satiety. Fat slows down digestion and absorption, which helps in making you feel full longer. This feeling of fullness is crucial in controlling food intake and managing weight. Choices A, B, and D are incorrect because fat's main role in providing satiety is related to slowing down digestion, not supplying a constant source of vitamins, speeding up digestion, or stimulating the release of digestive enzymes. While some types of fats can provide certain vitamins, the main purpose of fat in satiety is not vitamin supply.

Correct Answer: B

Rationale: The correct answer is B, 'Fat.' Fat provides 9 kcalories per gram, which is more than carbohydrates and proteins that provide 4 kcalories per gram each. Therefore, consuming 30 g of fat would yield a higher number of kcalories compared to the same amount of carbohydrates or proteins. Micronutrients do not significantly contribute to kcalories, making them an incorrect choice in this scenario.

Correct Answer: C

Rationale: The correct answer is C. Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds. Therefore, the number of double bonds is the chemical feature that distinguishes a saturated fatty acid from an unsaturated fatty acid. Choices A, B, and D are incorrect because the distinguishing factor between saturated and unsaturated fatty acids lies in the presence or absence of double bonds, not in the arrangement of carbon atoms, number of oxygen molecules, or food source.

Correct Answer: B

Rationale: The correct answer is B: Essential fatty acids are not manufactured by the body. These fatty acids must be obtained through the diet because the body cannot synthesize them. Choice A is incorrect because essential fatty acids can come from both animal and plant sources, not just from an animal source. Choice C is the correct characteristic of essential fatty acids. Choice D is incorrect because essential fatty acids are not produced by the body.

Correct Answer: C

Rationale: The primary function of protein in the diet is to build and repair tissues. Proteins are essential for the growth, maintenance, and repair of body tissues like muscles, skin, and organs. While proteins can be a source of energy, their primary role is not to supply energy, making choice A incorrect. Choice B is also incorrect as proteins do not synthesize vitamins; rather, they are essential nutrients themselves. Choice D is inaccurate because glycogen is a form of stored glucose in the body, not a function of protein.