Industry News | Biofortis Research

What Happens During the Screening Phase of a Nutrition Study?

Written by Biofortis Research | Apr 7, 2026 2:00:00 PM

Before any participant officially begins a nutrition study, there is an essential first step known as the screening phase. This stage plays a critical role in ensuring that the study is safe, accurate, and designed to produce meaningful results.

For participants, it is also an opportunity to better understand the study and determine whether it is the right fit. Let’s take a closer look at what happens during the screening phase of a nutrition study.

Why the Screening Phase Matters

The screening phase is designed to identify individuals who meet the specific criteria required for a study. In clinical nutrition research, these criteria, often called inclusion and exclusion criteria, help ensure that results are reliable and applicable to the intended population.

For example, a study focused on gut health may require participants within a certain age range, dietary pattern, or health status. Carefully selecting participants helps reduce variables that could skew results and ensures the data collected is scientifically valid.

Initial Pre-Screening

The process often begins with a pre-screening step, which may take place online, over the phone, or through a questionnaire. During this stage, potential participants answer basic questions about:

  • Age and general health
  • Medical history
  • Current medications or supplements
  • Dietary habits
  • Lifestyle factors such as activity level

This step helps researchers quickly determine whether an individual is likely to qualify before moving forward with more in-depth evaluations.

Informed Consent

If a participant appears to be a good fit, the next step is informed consent. This is one of the most important parts of the screening phase.

Participants are provided with detailed information about the study, including:

  • Its purpose and duration
  • Procedures involved
  • Potential risks and benefits
  • Privacy and data handling practices

This ensures that individuals fully understand what participation entails. They also have the opportunity to ask questions before agreeing to continue. Transparency at this stage is essential for ethical research practices.

Clinical and Nutritional Assessments

After consent is given, more detailed assessments are conducted. These may vary depending on the study, but often include:

  • Physical measurements (height, weight, BMI, etc)
  • Vital signs such as blood pressure
  • Blood or urine samples
  • Dietary intake assessments (food logs or recalls)
  • Questionnaires on lifestyle, sleep, or digestion

In some studies, advanced tools like metabolic testing or microbiome analysis may also be used. These evaluations establish a baseline, which is crucial for measuring changes throughout the study.

Eligibility Confirmation

Once all data is collected, researchers review the results to confirm eligibility. Not everyone who enters the screening phase will qualify, which is intentional. Strict eligibility criteria help maintain the integrity of the study and ensure participant safety.

If a participant does not qualify, they are typically informed promptly and may be considered for future studies that better match their profile.

What Participants Can Expect

The screening phase is typically straightforward and designed with participant comfort in mind. It may take anywhere from a single visit to a few appointments, depending on the complexity of the study.

Importantly, participation is always voluntary. Individuals can choose to withdraw at any point during screening without any obligation to continue.

Setting the Foundation for Quality Research

The screening phase is more than just a preliminary step–it lays the groundwork for the entire study. By carefully selecting participants and establishing accurate baseline data, researchers can generate insights that advance nutrition science and support the development of evidence-based health solutions.

For participants, it’s the first step in contributing to research that has the potential to improve health outcomes on a broader scale.

Research at Biofortis

Biofortis is dedicated to protecting consumer health throughout the world by delivering a wide range of testing and consultancy services to the food, supplement, and nutrition industries. Biofortis supports this mission in two ways–through clinical trials and sensory and consumer insights testing. We specialize in clinical research targeting foods, ingredients, and dietary supplements that affect body structures, function, and overall health. Contact us with any clinical trial or scientific consulting needs.