(800) 545-4772
Sign In
How DNA Testing Can Help Develop a Better Diet Plan

How DNA Testing Can Help Develop a Better Diet Plan

Reading Time: 4 minutes 23 seconds


DATE: 2020-01-14

With DNA tests getting increased attention these days, fitness professionals should know how they can use them to help their clients. There are many different options for DNA tests, from genetic screening for disease to researching ancestry or gaining insight into lifestyle habits.

One of the most popular areas within lifestyle testing is nutrition. Nutrition can be a difficult area to navigate with clients, but it is an important topic. Unlike the fitness plan, nutrition is all about what your client does the hours outside of the gym when they are not with you.

So, the question for fitness professionals is what does a DNA test tell me to help with a client's personalized nutrition plan? And how does that fit into the scope of practice of the fitness professional?

What Does a DNA Test Tell About Nutrition?

When a client completes a DNA test (also called a genetic test) for a diet plan, it will give them insight into how their body uses each of the macronutrients. It will also even show them how their body metabolizes caffeine.

This is a total game-changer for the client looking to lose weight. With a DNA diet plan, it takes the guess work out and guides the trainer to what is best for the client.


The first macronutrient to talk about is protein. A client's genetic profile shows a trainer one of two things for protein utilization. It will tell them that the person is either a "normal" genotype or an "enhanced" genotype.

What that means is simply how their body uses protein as a fuel source. Most people are going to fall into the category of "normal."

For the client falling into the "normal" genotype, it's important to note if they have a high protein or a lower protein diet it will not have a significant impact on their weight loss. Their body simply uses protein at a normal rate.

For their personalized nutrition plan, they should follow the 15-30% protein recommendation. Keeping in mind that going high protein isn't going to help them reach their goal faster.

On the other side, an "enhanced" genotype client will see an impact on their weight loss goals by following a high protein diet. These clients' personalized nutrition plans should consist of 25-35% protein to achieve their weight loss goals faster.


When it comes to carbohydrate utilization, the genetic results will be like protein utilization where a client's genetic profile will show either a "normal" genotype or an "enhanced" genotype.

When a client has a "normal" genotype for carbohydrates, it means whether they consume a low, moderate, or high complex carbohydrate diet coupled with a proper exercise program they will see the same weight loss results.

Now they do still need adequate carbohydrate intake to fuel their activities. It is ideal for these clients to focus on complex carbs as they will sustain them through activities longer.

Clients who have an "enhanced" genotype can benefit from a higher complex carbohydrate diet to reach their weight loss goals sooner.

These client's genes show they should focus on a diet that consists of 65% complex carbohydrates and lower fats to achieve their goals. It is still important that they get about 20% of their daily calories from fats as they are essential for the body to function.


When it comes to fat utilization in the body, a person's genetic profile will show either a "normal" genotype or a "low" genotype. A "normal" genotype means they have a normal ability to lose weight by following an eating plan that is low, moderate, or high in fat so long as they are expending more calories than they are consuming.

Those who have a "low" genotype for fat utilization are sensitive to the amount and type of fat in their diet. They are particularly sensitive to saturated fat and they lose less weight and hold more body fat when they are consuming a high-fat diet.

A general guideline for fat intake recommended by the Institute of Medicine is 20-35% of total daily calories. A high-fat diet typically consists of 30-40% of the day's total calories.

A low-fat diet is usually 15-25% of the day's total calories. It is always important to remind clients that they still need fat for their bodies to function, so they don't want to go too low when cutting fat.

Caffeine Metabolism

As one of the most widely consumed stimulants, lots of people are in the habit of consuming caffeine before exercise. While caffeine may not fall into the macronutrients, trainers need to understand how it affects their clients.

Too much caffeine for some can impact sleep and performance, which makes it an important topic to cover as part of their DNA diet plan. For caffeine metabolism, there are two possible genotypes: "fast" and "slow."

The majority of people fall into the "fast" genotype for caffeine metabolism, meaning their body metabolizes caffeine and it can help their performance.

These are the clients who can have a large dose of caffeine before a workout. Caffeine can help them perform better when used properly with their fitness plan.

For those who have a "slow" caffeine metabolism, they are the opposite. For these clients, one cup of coffee can affect them for hours after they drink it. They experience the opposite from caffeine pre-workout. If they have a slow genotype and they drink too much prior to exercise it can have a detrimental effect on their workouts.

So, when you put all of this together using a client's DNA, you as the fitness professional have what you could consider a road map for a client's personalized nutrition plan. And when they are seeing results, the likelihood of them sticking to the plan is much higher.

Scope of Practice

The biggest thing for fitness professionals to remember is to stay within their scope of practice. Regarding diet plans, this means giving clients recommendations and helping to guide them, but not giving them specific meal plans they must follow.

The DNA-based results will give you the road map to make those recommendations. As a personal trainer, it is your job to teach your clients how to make good choices and adapt to a healthy lifestyle rather than providing them with a concrete meal plan to follow. When you teach them to make good choices it will also help them be successful long-term.

If you are interested in learning more about how DNA testing can help provide personalized nutrition programs, check out ISSA's DNA-Based Fitness Coach.

Sign Up & Stay Connected

Receive $50 off your purchase today!