Although rachel has been trying to lose 10 pounds, she finds herself breaking her diet around 3 p. m. daily. rachel is likely experiencing low levels of mental alertness and sleepiness around this time of day because of the common daily highs and lows in her biological and psychological functioning, also known as?

Circadian rhythms

Explanation:

The body has its metabolism controlled by a biological clock that determines periods of higher and lower energy that occur directly related to the light / dark cycle of sunlight. These cycles are physical, mental and behavioral and are called circadian rhythms. The best example of a circadian rhythm would be the sleep routine of most people, which involves staying active and awake throughout the day and feeling tired and sleeping at night. As you can see from the question above, Rachel's circadian rhythm is out of control, which is why, in addition to talking about her diet, she is experiencing low levels of mental alertness and drowsiness around 3pm.