Updated December 05, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.
Prednisone belongs to a class of drugs known as corticosteroids. Steroids, as they are more commonly called, can be very effective medications for controlling inflammation. Many patients with inflammatory types of arthritis use prednisone or a similar corticosteroid medication to bring a flareup of symptoms under control. Other patients include one of the steroid medications as part of their usual medication regimen.
There are several side effects associated with prednisone and the other corticosteroid drugs.

Patients who use steroids are advised to take the lowest effective dose for the shortest duration possible to decrease the risk of adverse side effects. High doses and longterm use is linked to more severe side effects.

Weight gain is a known side effect of prednisone use and, perhaps it would be fair to say, the most frustrating. The pounds seem to pack on quickly. Attempts to lose the extra weight can seem futile, leaving patients depressed and feeling hopeless. But experts suggest there are things you can do to manage weight gain while on prednisone. First, you should understand how corticosteroids work and why weight gain occurs. Then, consider if suggested changes to your diet or lifestyle might help.

How Corticosteroids Work

Corticosteroids, natural or synthetic, are a group of chemically-similar hormones that have important functions within the body. Steroids play a role in regulating metabolism, immune function, inflammation and response to stress and injury. Naturally-occurring steroids, like cortisol, are produced by your adrenal glands.

Normally, the adrenal glands produce steroids that would be the equivalent of a low dose (about 5 mg) of prednisone daily. When corticosteroid drugs are prescribed at higher doses, they can help control inflammatory diseases.

How Prednisone Causes Weight Gain

Not everyone will gain the same amount of weight while on prednisone but most will have some degree of weight gain. Additionally, prednisone can cause a redistribution of fat, especially in the face, abdomen and back of the neck.
According to experts at The University of California San Francisco Medical Center (UCSFMC), weight gain associated with prednisone use is typically caused by fluid retention and higher calorie intake due to increased appetite. That's in addition to being less physically active because of pain and other consequences of chronic inflammatory disease.

You may think there is nothing you can do about those factors -- fluid retention, increased appetite and decreased physical activity. Think again. Let's consider what the experts recommend to help you manage weight gain from prednisone.

Managing Fluid Retention

A low-sodium, high-potassium diet can help control fluid retention. According to UCSFMC, you should not ingest more than 2,000 mg of sodium per day. You can achieve these dietary goals by avoiding high-sodium foods, especially processed foods, while increasing your intake of potassium-rich foods.

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Controlling Your Appetite

If increases in appetite have been subtle, you may not even realize this is an issue. Being aware of your increased appetite is the first step. Pay attention to your calorie intake and the nutritional value of the foods you eat.
Avoid processed sugars and simple carbohydrates, the so-called empty calories. These are digested quickly and just leave you hungry soon after. Instead, eat small but frequent healthy meals. Some recommend low-calorie, low-fat diets while others pitch low-carb, high-protein diets. Try both recommended courses and see what works for you.

• About.com Nutrition - Top 10 Foods Good for Low-Fat and Low-Carb Diets
• About.com Low Fat Cooking - Adopting a Low Fat Lifestyle

Increasing Physical Activity

Joint pain and other symptoms of inflammatory types of arthritis will make it difficult to exercise and keep activity at a high level. Most patients believe they can't do enough to burn calories. It is important to do something rather than nothing, though.
With the advice of your doctor or physical therapist, structure a daily exercise routine that takes into account your abilities. To whatever level is possible, include aerobic exercise and some strength training, which will help burn calories, build strength and slow bone loss. Make an effort each day.

Hold Yourself Accountable

Once you establish a diet and exercise regimen that will help you manage your weight, track your daily progress. You can do it by writing in a journal or keeping a chart on your computer. How you track your diet, exercise and weight is up to you, but make sure you do it. Accountability is a major factor that will help you successfully manage your weight while on prednisone.
<sub>Sources:

ILD Nutrition Manual: Prednisone and Weight Gain. UCSF Medical Center. Last updated 8/17/2011.
http://www.ucsfhealth.org/education/ild_nutrition_manual/prednisone_and_weight_gain/

Prednisone Information. The Johns Hopkins Vasculits Center. Accessed 10/12/2011.
http://www.hopkinsvasculitis.org/vasculitis-treatments/prednisone/</sub>