Chapter 8, Problem 5SC

Which of the following statements is not true? a. Essential nutrients can be synthesized by the body. b. Vitamins are required in small quantities for bodily function. c. Some amino acids can be synthesized by the body, while others need to be obtained from diet. d. Vitamins come in two categories: fat-soluble and water-soluble.

The hormone insulin enhances the transport of glucose (sugar) from the blood into most body cells. Its secretion is controlled by a negative-feedback system between the concentration of glucose in the blood and the insulin-secreting cells. Therefore, which of the following statements is correct? A decrease in blood glucose concentration stimulates insulin secretion, which in turn further towers blood glucose concentration. An increase in blood glucose concentration stimulates insulin secretion, which in turn lowers blood glucose concentration. A decrease in blood glucose concentration stimulates insulin secretion, which in turn increases blood glucose concentration. An increase in blood glucose concentration stimulates insulin secretion, which in turn further increases blood glucose concentration. None of the preceding is correct.

As a person ages, the number of body cells steadily decreases and energy needs decline. If you were planning an older persons diet, what kind(s) of nutrients would you emphasize, and why? Which ones would you recommend an aging person eat less of?