Sometimes people are so stressed out that it actually gets to the point where the last thing they are thinking about is food. So because of this, they do not eat and they lose weight. In addition to this, stress has many damaging effects on the body such as increased blood pressure, raising bad cholesterol levels, and over time, an increased risk of stroke and heart disease. Excess stress also lowers the immune systems ability to fight off disease.
Keep in mind that the most common reason that people who are stressed lose weight is because of a loss of appetite. Occasionally, stress can cause the thyroid gland to become hyperactive, which can also cause weight loss. Some experts also believe that stress may be linked to anorexia and bulimia.
You will actually hear much more about stress causing weight gain than about it causing weight loss, but stress can make some people lose weight.
Typically, the connection between stress and weight loss is psychological and not physical. When some people are stressed they lose their appetites. You have probably heard the idea of being too depressed or nervous to eat, right? This would be an example of stress causing loss of appetite. This, of course, leads to weight loss.
There are cases in which there actually is a physical connection between stress and weight loss, but the psychological connection is much more common.