If someone is feeling stressed or anxious, hormones present in blood communicate with cells to begin breaking down stored energy if the body needs it. in this situation, how does stress affect metabolic rate?

During stress, hormones like epinephrine and norepinephrine are secreted at higher levels. The sympathetic nervous system is also activated at that time. There is also an increase in blood pressure and improper insulin-dependent glucose disbursal. All of these lead to insulin resistance, and central obesity. Vascular complications also increase. The Basic Metabolic Rate (BMR) lowers down during the same because of disruption in the digestive system. 

Not true , they can fall or something