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Studying for the CNSC Exam

Updated: Feb 1


In November (2021), I added the credential of Certified Nutrition Support Clinician (CNSC) to my dietitian credential. The CNSC is a credential that enables all healthcare practitioners involved in nutrition support (tube feedings and TPN) to identify themselves as qualified caregivers. This exam can be taken by doctors, physician assistants, nursing and of course dietitians. The CNSC provides an avenue to demonstrate that you have attained the skills and knowledge necessary to provide quality nutrition support care. To learn more about the CNSC click here.


Since the early summer of 2021 I had been thinking about taking the Clinical Nutrition Support Clinician (CNSC) exam. There were 2 main reasons why I wanted to take it:


#1 It would give me a reason to dedicate a lot of time to improving my knowledge of nutrition support. While of course I learned a lot about TPN and tube feeding in my internship and of course learned a lot on the job, I hadn’t really sat down to study a lot of the why we did different things since I finished my dietetic internship and often relied on my senior dietitians and team leader dietitians to help me fill my knowledge gaps.


#2 My hospital (Brigham and Women’s Hospital), requires you to have your CNSC to enter Total Parenteral Nutrition (TPN) orders independently. Prior to receiving my CNSC I would need to plan out what I wanted to order for my patients, review it with a CNSC dietitian and the CNSC would then enter the order for me into the electronic medical record. Having my CNSC allows me to take on this responsibility and puts me in a good position to rise into more senior roles in our department as I continue in my clinical nutrition career. This credential will also allow me to move into managing home tube feeding and TPN patients as these patients continue to be followed and managed by a dietitian even after they leave the hospital.


The CNSC exam is only offered twice a year (May and October), so I had to think about when the best time would be for me to take this exam as I keep a very busy work schedule between the hospital and my business. My two options were October 2021 and May 2022 as I wanted to wait until I had 1 year of experience working as a dietitian at least to have a strong baseline knowledge. I personally did not want to wait until May to take it and with COVID still being in full swing I am home a lot more than I normally am which I knew would help me to dedicate more time for studying. Another consideration in the timing was my business. In the 1.5 years that I have owned my business each month it has continued to grow as I add more services to it and at the end of summer 2021, about 30% of my sales were from my recorded RD Exam Prep courses. As my recorded course library at this time has 30+ courses, I knew that I would be able to increase my marketing of recorded classes and reduce my 1:1 hours without harming my business/income, while still continuing to provide new and ongoing tutoring students with the services they needed. I knew that October was going to be the best time to take it for all these reasons and the fact that I had no idea what May 2022 was going to look like. Did I wait until the last day to sign up for the October 2021 test date… yes. At this point it gave me ~6 weeks to study.


Once I had my test booked, I reached out to my network of CNSC dietitians and asked them what their best advice was when it came to studying for the CNSC exam. Here is some of the advice I got:

  • Focus on practice questions and make sure to study pediatrics.

  • Purchase the ASPEN CNSC prep course.

  • Read the ASPEN core curriculum.

  • Review notes from your nutrition support rotation.

  • Know the medications and signs of deficiencies.

In general, for test taking, I think that asking someone how long they studied for an exam is not a helpful question to ask. Everyone’s schedule, learning style, baseline knowledge and quality of studying is different, so it really isn’t helpful to get this information from other people. Did I ask this question anyway… of course! Answers from my coworkers and friends ranged from 10 days to 5 months. Most common answer was about 3 months. Honestly none of these answers mattered because I only had 6 weeks to prepare for this exam since I started studying so late. Also during this time I had a vacation planned, was working 2 weekends at the hospital and was precepting a clinical 2 intern the last 3 weeks before my exam. Obviously not the ideal situation so I asked my boss for a total of 5 day off during this 6-week period to be able to use the time I’m normally at the hospital to study for the exam. I also reduced the amount of time I made available for clients/students by 50% in the month of October to allow me to use at least 1.5 hour each weekday to study for the exam.


Before I review how I studied for the exam, I also want to mention that I work in a position where I manage the TPN and tube feeding for my oncology patients every day so I felt that I came in with a lot of knowledge just from firsthand experience. Also, the nutrition department at Brigham is very team- and learning-focused, so I am able to gain a lot of knowledge of nutrition support in different populations from teaching rounds and our biweekly team meetings. Coming in with this experience allowed me to enter studying for this exam with a very solid knowledge of many of the topics on the exam. Topics that are on the exam that I had minimal experience in were neonatal/pediatrics, line care, home management and insurance/regulations.


The first thing I did to start my studying was to take a “practice exam” of 250 practice questions. I’m lucky that my job provides us with many practice CNSC questions, so I started with that to see what my baseline score was. Next, I started to read the ASPEN Adult Core Curriculum chapters that the exam covered. Again, I was very lucky and was able to borrow this book from one of my coworkers and did not have to buy it. As I read through the chapters I also took notes on any new material. I bought a notebook for my notes and organized it by chapter. Getting through all the reading was one of the most time-consuming tasks of my studying, but I was glad I read all of the material first. I finished the adult chapters in the first 3 weeks of studying.


After I had finished reviewing all the adult chapters, I bought the full ASPEN CNSC course. This course allows you to buy both the sections you need individually or to purchase the entire course at a discounted rate (also an additional discount if you are an ASPEN member). This course includes ~50 practice questions on each section and great explanations of each topic and covers both adult and pediatric. I found this course very beneficial. As a tutor for the RD exam, I knew how helpful it can be to have coursework to complete as it keeps you organized and focused. With this course I did 3 passes of each section:


1) Answer the questions without reviewing notes

2) Review explanations for all questions and add additional notes to my notebook. (I would do it right after completing a section.)

3) Retake the questions I initially answered incorrectly. (I did this 1 week before the exam)


At the end of the course and the week of the exam, I retook the same “practice exam” that I took at the very start of my studying and took the practice exam included with the ASPEN CNSC course. I do highly recommend doing this course as I felt very well prepared for the format and the types of questions that I would be asked on the exam. You also have access to the course for a year so if you are thinking of taking the CSNC in the next year you can always buy it early on. The week of the exam I also reread and highlighted all my notes which I thought was a good refresher of the material.


This exam does cover a lot of material and it also is formatted differently than the registered dietitian exam. Where the RD exam is a multiple-choice exam where you answer one question and have a maximum of 145 questions, the CSNC exam is a total of 250 multiple choice questions that is broken up into two 125 question sections in which you do have the ability to add notes to yourself on each question, flag questions and review all the questions before you submit the section. Going into the exam, I knew that I wanted to take advantage of being able to review the questions before submitting them, but with so many questions in each section I was worried that I wouldn’t remember my thought process on the question by the time I had finished all 125 questions and went back to review. As I had scrap paper for the exam for each section, I wrote out 1-125. After each question I answered I made a short note next to the question. If I knew I knew the answer 100% I would put a check next to the number and write my answer choice. If I was between 2 answers I would put a ~ , write which two I was between and flag the question. On questions that I was not sure on I would put a ● and flag it. When I went back for my final review before submitting for questions with a I would double check that I had selected the correct answer choice on the computer. For my flagged questions with a ● or a ~ I would completely reread the question and pick the answer that I had the best rationale for. This system was very helpful for me to stay organized through the 250 question, 4 hour exam.


As this exam is also 4 hours long, it is also important that as you prepare for it that you also practice how to stay focused during a set of 125 questions and time management. For me, going the practice exams at full length helped me to see how much time it was going to not only review the questions, but also to review all my answers. I ended up giving myself 1.5 hours to answer questions and 30 minutes to review for each section. Doing this I knew I had about a minute per question on average and it allowed me to better monitor my pace. I did take the full 4 hours, but I felt that this system did not end up with my rushing as I was finished with all my questions 30 minutes before the time ended and only had to review before submitting the final section.


I think the worst part of the exam is 100% that you have to wait 4-6 weeks for the results!

Overall, my study tips/advice for this exam are very similar to what I tell my RD Exam tutoring students. Start out with a study schedule and plan. This material is very dense, and you need to ensure that you will have enough time to move through all of the material. As I mentioned above, everyone’ study timeline is different depending on your baseline knowledge, schedule and learning style. I have always been someone who works best under pressure so my 6-week timeline worked best for me. Personally, I thought the ASPEN course was 100% worth the cost and would recommend it to anyone who wants a more structured course. I did also find the ASPEN Adult core curriculum helpful, but I’m not sure if I would have bought this if I had not been able to borrow it since I found the explanations on the prep course to be so in-depth and that is all I used for the pediatric section. I would recommend asking your network/job which study materials they have available or if you can be reimbursed for the cost of any prep materials. At my job I was able to get reimbursed for the cost of the exam after I passed, but I did have to purchase the ASPEN prep course.


I hope that this is helpful to anyone who is preparing for the CNSC exam! Check out my Nutrition Support Course for Registered Dietitians. If you have any additional questions about the exam don’t hesitate to reach out to me at danajfryernutrition@gmail.com.



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