source: http://www.calmclinic.com/anxiety/weight-loss

How Anxiety May Cause Weight Loss

It's well known that weight and overall health can contribute to anxiety. In fact, inactivity is one of the most common mistakes for those living with anxiety symptoms. Exercise reduces muscle tension, releases neurotransmitters that boost mood, burn away stress hormone, and help your body function properly – all of which are important for living with anxiety. Those that don't exercise become more prone to developing anxiety, which is why many with anxiety have weight management issues.

What you may not realize is that many of those living with anxiety also appear to have weight loss. Weight loss isn't necessarily an "anxiety symptom," but there does appear to be a significant number of people that lose weight with anxiety.

Weight Loss = Anxiety?

Unexplained weight loss is something that always deserves a doctor's visit. Thyroid disorders, HIV, some cancers, and diabetes are all potential causes of weight loss. But weight loss is also common in those with anxiety.

Being Safe With Weight Loss

Weight loss is generally seen as a good thing, but it's important that you lose weight safely. If you're losing weight without a healthy diet or exercise, then you're putting your body through a great deal of stress. It may also indicate a health issue, or an anxiety problem.

So play it safe when it comes to your health. Make sure you know what caused your weight loss. 

Why You Lose Weight

Stress and anxiety are commonly associated with weight gain, and for good reason – during times of anxiety, the body releases heavy amounts of cortisol, which is a hormone that contributes to weight gain – especially around the midsection. Anxiety also causes further inactivity as people lose interest in many of their activities, which can also increase weight gain.

Yet for various reasons, weight loss is also a problem that may occur with anxiety. There are several factors that cause this weight loss to occur:

• Lack of Eating – The most likely reason that those with anxiety lose weight is a disinterest in food. This is very common in those with depression, but plays a role with anxiety as well. When you have intense anxiety you start to lose your appetite. You start to feel as though you're genuinely not hungry and eat much less than you need to. You may not even realize how little you're eating, but in essence you're starving yourself, and that can cause massive weight loss very quickly. Unfortunately, it also eats away muscle and slows your metabolism so that if you start eating again, you're more likely to gain weight faster. If you have anxiety, you need to try to eat.
• Nervous Movement – Another often forgotten reason that you might lose weight with anxiety is because many of those suffering from anxiety are constantly moving. Some people develop nervous ticks and leg shakes. Others feel as though they have to get up and walk around, so they do more walking in their home. While some people completely shut down with anxiety, others unintentionally move more, and this can burn away calories.
• Sped Up Body – While long term anxiety leads to weight gain, the initial symptoms of anxiety and the fight or flight response actually do increase your metabolism, at least temporarily. Some people may experience more burned calories than others. 
• Lifestyle Changes – In rarer cases, it's possible that the way you change your lifestyle as a result of anxiety simply contributes to weight loss. For example, those with panic attacks tend to go out less and drink less as a result of their condition, and that means fewer calories. Others that used to exercise regularly may simply be losing muscle mass. The way people adjust to living with anxiety may also be a contributing factor.
• Over Compensation – Similarly, many people try to utilize various anxiety reduction strategies, including eating healthier and exercising more. The weight loss may be genuine, but because you have anxiety and because weight loss was not the intended outcome of the exercise/nutritional changes, the result may be that you worry more about your weight loss and health.

It's important to remember that anxiety itself makes you worry about things that shouldn't necessarily be worries. Weight loss may also simply occur naturally. But if you were not suspecting to lose weight, this can cause significant health concerns. It's simply the nature of anxiety to cause people to worry about their health.

Still, the most common reason that people lose weight is not eating. It's important that you do your best to eat a healthy meal with regularity.

Thyroid Conditions and Weight Loss

It should be noted that one of the few causes of anxiety that is purely physical is the development of hyperthyroid. With too much thyroid hormone, your body has too strong a metabolism, and this can cause rapid weight loss. Hyperthyroidism is also a cause of anxiety.

That's why, even though anxiety is often the cause of unexplained weight loss in people living with anxiety, it's still a good idea to check with a doctor. There are many simple tests to rule out hyperthyroidism.

Is There a Treatment?

Treating weight loss isn't necessarily related to anxiety itself. You simply need to make sure you're eating, talk to a doctor to rule out other symptoms, and keep exercising to ensure that you're promoting good health. There is nothing you can do in the short term to regain weight that's healthy for your body.

But in the long term, fighting your anxiety is going to be the key to ensuring that rapid weight loss doesn't continue.