How to Prepare for a DEXA Scan | Houston, TX

How Should You Prepare for a DEXA Scan or Metabolic Test?

Arrive properly hydrated but not over hydrated, fast for at least four hours with water permitted, skip calcium supplements for 24 hours, avoid heavy exercise beforehand, and wear clothing with no metal. These steps do not change your body composition. They change what the machine is able to read.

Full protocols for every service are provided before your appointment at DexaFit West Houston.

Why Preparation Affects the Reading

A DEXA scan distinguishes tissue types by how they absorb energy. Water content, recent food, and even metal fasteners all influence that measurement.

The scan is measuring your body under the conditions present on that day. If those conditions differ between visits, some of the change you see is the conditions rather than you.

The goal is not perfection. It is consistency across scans.

The Preparation Steps That Matter Most

Each of these addresses a specific source of variability.

• Hydration, since water content affects lean mass measurement in both directions
• Fasting for at least four hours, because food and drink in your system add measurable mass
• No calcium supplements in the previous 24 hours, which can affect bone readings
• Limited exercise beforehand, as hard training shifts fluid distribution
• No metal on clothing, which interferes with the scan directly

Water is fine during the fasting window and is in fact encouraged, since arriving dehydrated causes its own problems.

Why This Matters Most for Repeat Testing

A single scan gives you a snapshot. The real value arrives with the second one, when you finally have a comparison.

That comparison only holds if conditions were similar. Scanning fasted in the morning, then scanning after lunch three months later, introduces variability that has nothing to do with your training.

Same time of day, same preparation, same hydration approach. That is what makes a difference between scans trustworthy.

Preparation for Other Tests

Requirements differ by service, and assuming they are identical is a common mistake.

A metabolic rate test requires a longer fast and a period of rest before the measurement, since the goal is to capture your resting state specifically.

A VO2 Max test asks for the opposite in some respects: avoid a hard session the day before, arrive fed enough to work hard, and bring appropriate footwear.

Our full pre test protocols cover each service individually.

What Happens If You Did Not Prepare Perfectly

Tell us. That is genuinely the whole answer.

Knowing you had breakfast, trained that morning, or took a supplement lets us interpret the numbers with appropriate context rather than reading a variation as a real change.

Nobody is judging your preparation. We simply cannot account for what we do not know about.

Frequently Asked Questions

Can I drink water before a DEXA scan?

Yes. Water is permitted and encouraged during the fasting window. Being properly hydrated produces a more reliable reading than arriving dehydrated does.

What should I wear?

Comfortable clothing with no metal at all. Zippers, underwire, buttons, and hardware can interfere with the scan. Athletic wear without metal components works well.

What if I worked out that morning?

Let us know when you arrive. Exercise shifts fluid distribution, which can influence the reading. We can note it against your results or discuss rescheduling if it would meaningfully affect the comparison.

Prepare Once, Compare Forever

Ten minutes of preparation is what separates a number you can trust from one you cannot. Book your appointment at DexaFit West Houston, 9432 Katy Fwy #400, Houston, Texas 77055, or call (713) 834-4353.

Published by DexaFit West Houston | Dr. Gregory Burzynski | Serving West Houston & Harris County, TX | (713)834-4353

Educational purposes only. Not medical advice.