Answer:
Time of day - External
Exercise - Internal
Fat mass and cell size - Internal
Eating cues - External
Temperature - External
Hormones - Internal
Explaination: The external factors are those factors that have no direct impact or effect in controlling the food inside the body. They can only play a sizeable role on how the food is controlled outside the body, hence they are external.
The internal factors are those factors who their impact or effect on controlling the food is directly felt inside the body.