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Product & Plan FAQs

Medical Conditions

What medical conditions would prohibit my use of a Medifast Plan?

The Company (“We”) recommends that you consult your healthcare provider prior to starting any weight loss program, and during the course of your weight loss program. Do NOT use any Medifast Program if you are pregnant or under the age of 13.

Before starting a weight loss program, talk with your healthcare provider about the program and about any medications or dietary supplements you are using, including especially Coumadin (warfarin), lithium, diuretics, or medications for diabetes, high blood pressure or thyroid conditions. Do not participate in any Medifast Program until you are cleared by your healthcare provider if you have or have had a serious illness (e.g. cardiovascular disease including heart attack, diabetes, cancer, thyroid disease, liver or kidney disease, eating disorders such as anorexia or bulimia), or any other condition requiring medical care or that may be affected by weight loss.

The Medifast for Teens plan is the only Medifast program appropriate for teens (13 to 17 years of age). The Medifast GO! Plan or 5 & 1 Plan is NOT appropriate for teens, sedentary older adults (65 years and older), nursing mothers, people with gout, some people with diabetes, and those who exercise more than 45 minutes per day – if you fall into one of these categories, please consult your healthcare provider and refer to www.medifast1.com for other Medifast plans that may be appropriate. For special medical or dietary needs, including food allergies, refer to our program information online and consult your healthcare provider. Do not consume a Medifast product if you are allergic to any of that product’s ingredients which are listed on the product packaging and on the Medifast website.

We recommend drinking 64 ounces of water each day. Consult with your healthcare provider prior to changing the amount of water you drink as it can affect certain health conditions and medications.

NOTE: Rapid weight loss may cause gallstones or gallbladder disease. While adjusting to the intake of a lower calorie level and dietary changes, some people may experience dizziness, lightheadedness, headache, fatigue, or gastrointestinal disturbances (such as abdominal pain, bloating, gas, constipation, diarrhea, or nausea). Consult your healthcare provider for further guidance on these or any other health concerns. Seek immediate medical attention if you experience muscle cramps, tingling, numbness, confusion, or rapid/irregular heartbeat as these may be a sign of a more serious health condition.

For avoidance of doubt, the Medifast programs and products are not labelled, advertised or promoted for any specific medicinal purpose, i.e. treatment or prevention, implied or otherwise, of any disease or disorder, including its related conditions.

The Medifast programs, products and any of its materials and/or information do not in any way constitute medical advice or substitute for medical treatment. As individuals may have different responses to dietary products or changes in diet, consult with your healthcare provider regarding any medical concerns.

For further information regarding this Medical Disclaimer, Call Nutrition Support at 1-800-509-4401 or email at nutritionsupport@medifastinc.com.

What medications may limit and/or prohibit my use of a Medifast Plan?
  • When following a weight-loss program, talk with your health care provider about any prescription medications, especially:
    1. Diabetes medications
    2. High blood pressure medications
    3. Diuretics
    4. Coumadin® (warfarin)
    5. Lithium
    6. Thyroid conditions

    Before starting a weight loss program, talk with your healthcare provider about the program and about any medications or dietary supplements you are using, including especially Coumadin (warfarin), lithium, diuretics, or medications for diabetes, high blood pressure or thyroid conditions.

What specialized programs does Medifast offer for individuals with specific needs and preferences?
Our special programs can help you get the most out of Medifast. For more information about successfully using Medifast, please refer to our specialized program guides for: For more information about successfully using Medifast based on your specific needs, please refer to the following handouts or information: We recommend you discuss your medical conditions and weight-loss plans with your health care provider before starting any Medifast Plan.
Can I use Medifast if I am currently using thyroid medication?

Our Thyroid Medication, Soy, and Your Medifast Plan (PDF) handout provides information on how to successfully use Medifast for individuals taking thyroid medication. We recommend discussing your medical conditions and weight loss plans with your health care provider before starting the Medifast Program.

If your doctor has prescribed thyroid medications like levothyroxine, Synthroid® or Levoxyl®, you should understand that eating soy may slow down your body's absorption of these drugs. You should wait one to three hours before or after taking your thyroid medication before eating any Medifast Meal containing soy protein—or choose a soy protein-free meal instead. Your healthcare provider may want to monitor your thyroid hormone levels during your weight-loss program.

For information on soy-free and soy protein-free products, please refer to our Allergen/Dietary Information (PDF).

Can I use Medifast if I have had gastric bypass surgery?

In some cases, surgery alone may not be enough for maintaining a healthy weight over the long term, and you may benefit from a nutritional meal plan to control calories. Regardless of the procedure you've undergone, Medifast can help you achieve and maintain your weight-loss goals, safely and effectively.

Please refer to our Bariatric Surgery and Medifast Information Sheet (PDF) for more information. We recommend you discuss your medical conditions and weight-loss plans with your health care provider before starting the Medifast Program. Your health care provider may want to monitor your labs and medications, or can help determine a calorie level that's appropriate for you.

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