If you're scheduled for a DEXA (Dual-Energy X-ray Absorptiometry) scan, you may be wondering if you should eat or drink beforehand. The answer depends on what part of your body is being scanned and whether you want the most accurate results.
Here’s a detailed guide on eating and drinking before your DEXA scan and what factors can affect your results.
Can You Eat Before a DEXA Scan?
- Yes, you can eat before a DEXA scan—there are no strict fasting requirements.
- However, for the most accurate body composition results, it’s best to avoid large meals within 2-3 hours before your scan.
📌 Why? Food and beverages can temporarily affect body composition readings, especially when measuring lean mass, fat mass, and hydration levels.
👉 Example: If you drink a large coffee or eat a salty meal right before your scan, your body may retain more water, slightly altering lean mass readings.
What About Drinking Water, Coffee, or Tea?
- Water: It’s fine to drink a small amount of water before your scan, but avoid drinking excessive amounts, as this can artificially inflate your lean mass measurement.
- Coffee & Tea: Best to avoid before the scan, especially if they contain milk, sugar, or artificial sweeteners—these can affect hydration levels and metabolism.
- Alcohol & Sugary Drinks: Avoid 24 hours before your scan, as they affect water retention and body composition measurements.
📌 Best Practice: Stay hydrated, but avoid excessive liquid intake right before your scan.
What Can Throw Off a DEXA Scan?
For the most accurate results, avoid the following before your scan:
- Large meals (2-3 hours before scan) – Can temporarily increase body weight & lean mass readings.
- Caffeinated drinks (coffee, energy drinks, tea) – Affects hydration & metabolism.
- Alcohol (24 hours before scan) – Dehydrates the body, impacting body composition readings.
- Vigorous exercise (24 hours before scan) – Increases water retention in muscles, altering results.
- Metal jewelry, belts, or clothing with zippers – Can interfere with DEXA scan accuracy.
👉 Example: If a person drinks a lot of water or eats a big meal before the scan, their lean mass and weight may appear slightly higher than normal.
Can You Have a DEXA Scan on an Empty Stomach?
- Yes, you can have a DEXA scan on an empty stomach, and it may provide the most consistent body composition readings.
- Many people prefer to schedule their scan in the morning before eating or drinking much to minimize variability in hydration and weight.
📌 However, fasting is not required unless instructed by your doctor for specific medical reasons.
👉 Example: If you schedule your scan early in the morning, you may get a more stable baseline measurement of fat and lean mass compared to scanning later in the day after eating multiple meals.
What About Taking Supplements Before a DEXA Scan?
📌 Some supplements can impact your DEXA scan results:
- Creatine & Pre-Workout Supplements – Increase muscle water retention, affecting lean mass readings.
- Electrolyte Supplements (Sodium, Potassium, Magnesium) – Can influence hydration balance.
- Calcium & Vitamin D Supplements – Do NOT take calcium supplements within 24 hours before a bone density scan, as they can interfere with bone mineral density (BMD) readings.
👉 Example: If you take creatine daily, your DEXA scan may show slightly higher lean mass due to increased water retention in muscles.
Best Practices for Accurate DEXA Scan Results
To ensure consistent and accurate body composition or bone density results, follow these pre-scan tips:
- Eat normally, but avoid large meals 2-3 hours before the scan.
- Stay hydrated, but avoid excessive water intake right before your appointment.
- Skip coffee, tea, and alcohol for at least 12-24 hours before your scan.
- Avoid intense exercise or weightlifting the day before your scan.
- Wear lightweight, metal-free clothing for the scan.
- If getting a bone density scan, do NOT take calcium supplements within 24 hours before your test.
🚀 Following these steps will help ensure your DEXA scan provides the most reliable and accurate results.
The Bottom Line: Can You Eat Before a DEXA Scan?
- Yes, you can eat before a DEXA scan, but for the most accurate results, avoid large meals within 2-3 hours of the scan.
- Drink water in moderation, but avoid excess liquids, caffeine, or alcohol before your scan.
- Avoid exercise, high-sodium foods, and supplements like calcium (for bone scans) before your test.
- Morning scans on an empty stomach may provide the most stable results for body composition analysis.
🚀 Want to track your body composition or bone health with precision? A DEXA scan is the best way to get real, data-driven insights.
Book Your DEXA Scan in San Francisco at KALOS Today
For the most accurate body composition and bone density tracking, schedule your DEXA scan at KALOS. Whether you're monitoring fat loss, muscle gain, or osteoporosis risk, we provide the most precise and data-driven results.
📍 Schedule your DEXA scan today at KALOS—because real data leads to better results.
