What Could Be Causing Your Appetite Loss? 10 Possible Reasons

9. Hypothyroidism

The thyroid gland converts food and oxygen into energy. If it gets sluggish in its production of hormones, a condition called hypothyroidism, the result is fatigue, among other symptoms. Since the body requires less energy in this slowed-down state, it doesn’t need as many calories from food. Even though a person with this condition has a loss of appetite and eats less than usual, they might gain weight when calories they don't burn for energy are stored as fat.