RD - Commission on Dietetic Registration (CDR) Practice Test

What type of study involves participants being randomly assigned to different diet plans to assess effects on serum triglyceride levels?

1. Descriptive study

2. Case-Control study

3. Qualitative study

4. Experimental study

The correct answer is: Experimental study

An experimental study is characterized by its design, which involves the random assignment of participants to different groups, in this case, various diet plans. This randomization is crucial as it helps to minimize bias and allows for a better assessment of the causal effects of the dietary interventions on a specific outcome—in this scenario, the serum triglyceride levels. In experimental studies, researchers can manipulate one or more independent variables (the diet plans) and observe the impact on the dependent variable (serum triglyceride levels), providing strong evidence for cause-and-effect relationships. This type of study typically involves controlled conditions and systematic observation, making it superior for determining the efficacy of different interventions in clinical settings. The other types of studies outlined do not involve this level of manipulation or control. Descriptive studies primarily focus on characterizing populations or phenomena without inferring causal relationships. Case-control studies examine the association between an exposure and an outcome by looking backward in time, while qualitative studies explore subjective experiences and perspectives rather than quantifying outcomes. Therefore, the structure and objectives of an experimental study clearly distinguish it as the correct choice for the scenario described.