Many studies have indicated that there is some genetic influence on body weight and composition. Researchers have established a variety of theories that attempt to explain why some individuals gain weight more easily than others and why weight can be so difficult to change long-term. Choose the correct statement about theories regarding genetic influence on weight status.

a. The thrifty gene theory suggests that some individuals have a "thrifty metabolism," which could help a person survive when food is scarce.

b. According to recent research, the FTO gene may increase feelings of satiety.

c. The set point theory indicates that bodies are meant to stay within a narrow weight range, which cannot be changed long-term.

d. Drastically reducing calorie intake causes BMR to increase, which helps individuals deviate from their "set point" for weight

The thrifty gene hypothesis postulates that due to dietary scarcity during human evolution, people are prone to obesity by storing energy as fat, an ability to take advantage of rare periods of abundance and this is advantageous during times of food availability. individuals with greater adipose reserves would more likely survive famine. This tendency to store fat could lead to obesity.

FTO is an enzyme that is encoded in humans by FTO gene located on chromosome 16. Increase in this enzyme is associated with the regulation of energy intake but not feeding reward. Also, the set point theory indicates that bodies are meant to stay within a narrow weight range but it is susceptible to chnage overtime.