Which of the following foods is the best source of omega-3 fatty acids?

Correct Answer: A

Rationale: Salmon is the correct answer as it is a rich source of omega-3 fatty acids, specifically EPA and DHA, which are known to be beneficial for heart health. Chicken, spinach, and eggs do not contain significant levels of omega-3 fatty acids compared to salmon. While eggs do contain some omega-3s, the amount is considerably lower than what is found in fatty fish like salmon.

Correct Answer: C

Rationale: The correct answer is Vitamin D. Vitamin D is synthesized in the skin when it is exposed to sunlight. This process allows the body to produce Vitamin D naturally. Vitamin A (Choice A) is found in foods like liver and carrots and is not primarily obtained from sunlight. Vitamin C (Choice B) is commonly found in fruits and vegetables. Vitamin E (Choice D) is present in foods like nuts and seeds and is not primarily obtained from sunlight.

Correct Answer: D

Rationale: Proteins, carbohydrates, and fats are macronutrients that provide energy in the form of calories when consumed and metabolized by the body. Each gram of protein or carbohydrate provides about 4 calories, and each gram of fat provides about 9 calories. On the other hand, vitamins do not provide energy or calories. They are micronutrients that are essential for various biochemical and physiological processes in the body, including the metabolism of macronutrients. However, they do not contribute directly to the energy supply. Therefore, the correct answer is 'D: Vitamins'. Choices A, B, and C (Proteins, Carbohydrates, and Fats) are incorrect because they are macronutrients that do provide energy/calories when metabolized.

Correct Answer: B

Rationale: Energy drinks are known for causing a variety of health issues, including nervousness, seizures, and an increased risk of dental caries due to their high sugar content. However, they do not cause bradycardia, which is a slow heart rate. Instead, energy drinks are associated with causing an increased or rapid heart rate, known as tachycardia. Therefore, out of the listed options, bradycardia is the condition not caused by energy drinks.

Correct Answer: B

Rationale: The correct answer is B: 7 kcal/g. Alcohol provides approximately 7 kilocalories per gram, making it a significant source of energy or 'empty calories' in the diet that do not contain any nutrients. 'Empty calories' refer to the calorie content without the presence of essential nutrients. Choices A, C, and D are incorrect. The energy values of 3 kcal/g, 10 kcal/g, and 25 kcal/g are not accurate for alcohol; instead, they may pertain to other nutrients such as carbohydrates (approximately 4 kcal/g), fats (approximately 9 kcal/g), and oils (approximately 9 kcal/g).