Keith has struggled with his weight throughout life.Though he would very much like to be thinner and healthier, he claims to have little time for exercise and says he has “no taste for vegetables.” With those limitations in mind, Keith has started researching extreme diets he thinks might fit his lifestyle and help him lose weight. He stumbled upon some information about a “carnivorous” diet where he would eat only meats and avoid grains andvegetables. Keith likes this idea, since he very much likes to eat meat products. According to the information he read, the idea would be to entirely eliminate carbohydrates from his body and force his cells to use fats for energy. Without carbohydrates around, his cells would store away less fat and would instead burn that fat. Controversies about the impact of such a diet on a person’s cardiovascular health have not deterred Keith from considering this diet. Keith is a little concerned, though, since he also read somewhere thatour brains cannot use fats for energy. He certainly doesn’t want to hurt his brain cells by depriving them of energy!

Questions

1. Discuss one disadvantage to relying only on fats, and not carbohydrates, for energy via aerobic metabolism.
2. If Keith adopts an all-meat diet, what vitamins should he make sure to supplement his diet with to avoid deficiency?
3. If brain cells cannot break down fatty acids for energy, and if Keith eliminates all carbohydrates from his diet, will Keith’s brain cells die off? How will they receive an energy supply for aerobic metabolism?