The Importance of Lab Tests for Weight Management

Weight Loss  /  Blog

The Importance of Lab Tests for Weight Management

Tessa Chatham Registered Nurse

Written by Tessa Chatham Registered Nurse

Tessa Chatham Registered Nurse

Tessa Chatham Registered Nurse

Tessa is a MSN prepared Registered Nurse with 12 years of critical care experience in healthcare. When not practicing clinical nursing, she enjoys academic writing and is passionate about helping those affected by medical aliments live healthy lives.

Linda Anegawa, MD, FACP

Reviewed by Linda Anegawa, MD, FACP

June 14, 2022 / Read Time 4 minutes

Updated March 1, 2023

What Labs and Measurements Do You Need to Help with Weight Management?

Obesity is a medical condition that puts people at risk for other chronic and serious health problems. People with obesity account for more than 30% of U.S, adults and 20% of U.S. children, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Having excess body weight can lead to other health conditions such as heart disease, type 2 diabetes, high blood pressure, arthritis, and certain types of cancer. 

If you are concerned about your weight, there are certain numbers that will be important for you and your doctor to know.

First, a screening calculation called the body mass index (BMI) will be done by your doctor to determine if your weight may put you at risk for other diseases. BMI results are categorized into five main groups:

  • <18.5 - Underweight

  • 18.5-24.9 - Healthy weight

  • 25-29.9 - Overweight

  • 30-34 - Class 1 Obesity

  • 35-39 - Class 2 Obesity

  • 40+ - Class 3 Obesity 

It is important to understand that the BMI is only a screening tool, and an approximation of risk. For example, even if your BMI falls in what is known as the healthy range, it is still possible for you to be affected by weight-related metabolic disease. This is why your doctor will also use lab tests and perhaps even other measurements to guide your weight management treatment plan. This may include completing a blood test, which will help provide accurate information that will allow the doctor to determine a diagnosis as well as care options for you.

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

Why Do You Need Labs for Weight Management?

Labs are used to check certain items that pinpoint possible sources of weight gain. Checking labs will screen for underlying conditions, and can help determine if weight loss medications can be used safely. Labs can also determine what type of medication and lifestyle change may work best for your body. For these reasons, labs are often required before discussing a prescription for weight management medication.

What Blood Tests are Done for Weight Loss? 

Blood tests which are typically done measure general blood chemistry, liver and kidney function, blood count, insulin sensitivity, thyroid hormone levels, and cholesterol. The following are common measurements taken as part of a blood test for weight loss:

  • CMP - Used to measure metabolic reactions in the body, electrolytes, and liver/kidney function.

  • Vitamin D (25-hydroxy) - Obesity can contribute to vitamin D deficiencies.

  • A1c - Used to determine if you have diabetes or are at risk for diabetes.

  • CBC - Used to determine blood count, immune function, platelet counts, and to screen for anemia.

  • Lipid Panel - Used to determine cholesterol levels.

  • TSH - Used to check thyroid function.

Other tests that are done for managing weight loss treatment include your blood pressure and pulse measurements. Carrying excess weight can increase your risk for high blood pressure and heart problems. A baseline blood pressure and pulse measurement is also important prior to prescribing weight loss medications, as some of these can affect blood pressure and pulse.

Is There a Blood Test to Check Your Metabolism?

Because weight regulation is complex, there is no one blood test to check your metabolism. Blood tests are checked to determine if there may be imbalances that can contribute to a slower metabolism. For example, if insulin resistance is found by testing your fasting insulin and glucose levels and then using an equation to calculate what is known as the HOMA-IR, this can be a contributor to unwanted weight gain in some individuals.  The good news is, if insulin resistance is present, diet changes can help.  

Thyroid hormone is also generally checked, especially the TSH (thyroid stimulating hormone). The TSH is the master regulator of the entire thyroid system. Low thyroid hormone levels can contribute to small amounts of weight gain over time. However, when the TSH level is abnormal, this is more likely to be a result of the weight gain than a cause. Your doctor can help you decipher the meaning of abnormal thyroid hormone levels and what action would need to be taken next.

How Often Should You Get Labs Done for Weight Management?

On average, labs should be done after your initial visit with your doctor, and then at least once a year for weight management. Depending on your initial results though, and your treatment plan and care goals, your doctor may order labs more frequently. It can also be exciting and motivating to obtain more frequent labs to see the results of your progress, too.

How Much Do Labs for Weight Management Cost?

Labs for weight loss management are affordable. Labs for weight loss are considered to be prevention medicine, which is generally covered by health insurance plans. Cash pay reduced rate lab options may also be available, and this can be discussed with your physician.

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

Talk to a Doctor About Lab Tests for Weight Management

If you are concerned about your weight or wish to discuss your body mass index, talk with one of our trusted doctors to get an order for lab tests. Labs can highlight important information that is used to guide weight loss treatment plans. Book an appointment today to speak with a board-certified primary care doctor about weight management options. 

Read More About Weight Management

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