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Future Fit Traning

Personal Trainer’s Role in Nutrition

Nutrition can be a confusing topic for many clients - with so much, often conflicting information on social media, websites and magazines. As a personal trainer, you can play an important role in helping clients clear the confusion and have a better understanding of how to apply nutrition to their lives.

In this post, guest author Human Kinetics discuss the personal trainer’s role in nutrition, adapted from the latest edition of NSCA’s Essentials of Personal Training, Third Edition.

Nutrition can be a confusing topic for many clients, with so much, often conflicting information on social media, websites and magazines. As a personal trainer, you can play an important role in helping clients clear the confusion and have a better understanding of how to apply nutrition to their lives.

How much nutrition information and advice can you give as a personal trainer?

It is well within the personal trainer’s scope of practice to address misinformation and to give general advice related to nutrition for physical performance, disease prevention, weight loss, and weight gain. An important part of the core knowledge, from the standpoint of both ethics and safety, is the ability to recognise more complicated nutrition issues and know who to refer clients to.

Referral to a nutrition professional is indicated when the client has a disease state (e.g., diabetes, heart disease, gastrointestinal disease, eating disorder, osteoporosis, elevated cholesterol) that is affected by nutrition. This type of nutrition information is called medical nutrition therapy and falls under the scope of practice of a licensed nutritionist, dietitian, or registered dietitian (RD). A referral is also indicated when the complexity of the nutrition issue is beyond the competence of the personal trainer, which will vary. Personal trainers should find several nutrition professionals they feel comfortable referring their clients to and with whom they can communicate about clients. The European Federation of the Association of Dietitians, provides links to each country’s dietitian organisation.

Tomatoes, lettuce and a yellow pepper on a chopping board

Conducting a Dietary Assessment

Should a client seek nutrition information that is within the scope of your practice as a personal trainer,  you may want to assess the client’s diet. If the request is out of the scope of your practice, you can work alongside a dietitian who assesses the client’s diet.

A complete nutrition assessment includes dietary data, anthropometric data, biochemical data (lab tests), and a clinical examination (condition of the skin, teeth, and so on). Although personal trainers are usually not involved in the comprehensive assessment, you may want to be familiar with the individual components of a comprehensive dietary assessment so you can work with the dietitian to provide your clients with the best service possible.

Gaining Dietary Intake Data

Before you can give valid nutrition advice, gleaning some information about the client’s current diet is imperative. How complete is the client’s current diet? Is the client allergic or intolerant to certain foods? Is the client following a specific diet (e.g., vegetarian)? Restricting food groups? Dieting to lose weight? Is the client a sporadic eater? Has the individual just adopted a new way of eating? The answers to these questions and others may influence your advice to the client.

Gathering dietary intake data is a simple concept, but it is extremely complex to do. If under your scope of practice, can choose from three methods for gathering dietary intake data:

  • Diet recall
  • Diet history
  • Diet record

In a diet recall, clients report what they have eaten in the past 24 hours. With a diet history, clients answer questions about usual eating habits, likes and dislikes, eating schedule, medical history, weight history, and so forth. The diet record is typically a log, filled out for three days, in which the client records everything consumed (foods, beverages, and supplements).

The three-day diet record is considered the most valid of the three methods for assessing the diet of an individual. However, a valid record requires scrupulous recording as well as scrupulous analysis. The pitfall of this method is that recording food intake usually inhibits regular eating patterns, and recorded intake thus underestimates true intake. To get useful data, you should ask only the most motivated clients to complete this process. The diet recall or diet history is more appropriate for many clients. To facilitate better tracking, and in the cases where a diet history or recall is used, diet tracking apps may be useful because they can be used on the go, as the individual consumes food, and sometimes have features such as food barcode scanning.

Feedback notes

Evaluating a Client’s Diet

One way to evaluate a clients’ diet is by using diet analysis software. Computerised analysis can provide a snapshot of a client’s diet, including vitamin and mineral intake. However, it is important that the client accurately and completely record the usual intake for at least three days. The client should input the amount of each food and beverage, specify how it was cooked, and give the brand name versus the generic term.

Even if the diet is recorded perfectly, the analysis will not be completely accurate because all software programs have shortcomings. For example, some foods the client eats are not in the database, necessitating substitutions or typing in the actual food data.

Not all personal trainers will have access to computerised dietary analysis. As a result, this is an area in which many personal trainers turn to dietitians for assistance. Another option is to refer motivated clients to websites or apps where they can enter their own diet and receive feedback. These tools are excellent resources because they put the responsibility on the client. Additionally, some clients feel more comfortable asking questions and reporting intake in private situations.


Once a dietary assessment has been conducted, you will then be in a position to explore a client’s energy requirements and nutritional needs, either on your own or with the help of a nutritionist.

Helping clients build skills and develop healthy eating habits requires a systematic process that is repetitive and cyclical to continually help clients progress toward their goals. The following five-step process can be employed to enhance success:

Step 1: Assess and gather data about goals, current intake, anthropometrics, and health status. This provides baseline information to see how clients are progressing across many domains—food intake, weight, body composition, health markers, performance, and so on.

Step 2: Collaboratively create a solution-focused action plan and outline possible next steps. What are they already doing well? How can they do more of that? What skills do they already have that can be leveraged?

Step 3: Collaboratively choose some next steps and have the client implement them. Prioritise the next steps from Step 2 and choose the next few the client will tackle. Agree together on how to assess their consistency with those actions.

Step 4: Observe and monitor the outcomes of those steps. Were they consistently able to implement the chosen actions? Did those chosen actions lead to progress toward their goals?

Step 5: Assess and gather data about behaviours and outcomes (then repeat Steps 2 through 5). If clients weren’t able to consistently implement the chosen actions, why not? What got in their way? If they were able to do it sometimes, what was different about those times? How can they do more of that? If those actions did not lead them toward their goals, do the actions need to change?

If you have found this post useful, you can find much more information on nutrition and all aspects of the personal trainer’s role in NSCA’s Essentials of Personal Training, Third Edition, published by Human Kinetics.