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The Promise and Perils of Personalized Nutrition: Separating Fact from Fiction

What if you could eat the right foods, tailored just for you, to keep your body and mind as healthy as possible and maximize your well-being and lifespan?

That’s the premise behind personalized nutrition, which aims to use technologies like DNA testing and health metric tracking to optimize diets. It’s an interesting idea and maybe someday we’ll be able to have individually designed diets. Unfortunately, the scientific proof for these diets isn’t there yet. 

We connected with Nicole Hahn, a clinical dietitian with Banner – University Medicine, to learn the facts and fiction behind this buzzy concept. 

Tailoring your diet to meet your needs

Personalized nutrition is a field that aims to tailor diet advice to each person’s needs and goals. The idea is that, for example, a 70-year-old white farmer in Colorado with high blood pressure has different needs than a 30-year-old Black lawyer in Phoenix with a high risk of breast cancer.

At a base level, different people indeed have different nutritional needs. And some tailored diets have solid benefits. For example, tailored diets can help people avoid foods that trigger an allergic response. They can help control conditions like diabetes and kidney failure. 

They may also support weight loss. “Calorie-controlled diets with adequate protein, vitamins and minerals from a variety of foods can help people on their weight loss journeys,” Hahn said.

Other factors that might influence the types and amounts of foods you need in your diet include:

  • Genetics, which can affect how your body processes food and responds to nutrients. 
  • Metabolism, which is how fast your body converts food to energy (burns calories).
  • Lifestyle, since physical activity, stress and sleep can impact your need for nutrients.
  • Health status, since you may need to choose more or less of certain foods depending on your health. For example, people with celiac disease can’t eat foods that contain gluten.
  • Food preferences, since you’ll want to eat foods that you enjoy and that are part of your culture.
  • Gender, since men and women have different nutritional needs.
  • Socioeconomic status, since your finances play a role in what you can afford to spend on food.

What is personalized nutrition?

The idea behind personalized nutrition takes the concept a bit further. The theory is that if you know details about your health and life, you can figure out the type of diet you should eat. 

People who promote personalized nutrition point to DNA testing and wearable devices as ways to get the information you need to create the perfect diet for your needs:

  • DNA testing may give you insights into your genetic makeup and how it affects your nutritional needs.
  • Wearable devices like fitness trackers can monitor your activity levels, heart rate and sleep patterns. Continuous glucose monitors (CGMs) can track your blood sugar.

However, while there’s hope that this data can point you toward the best diet, experts don’t yet know how to design a diet optimized for each individual.

“If anyone is saying they can sell you a personalized DNA profile diet, be cautious. Science does not support this yet,” Hahn said.

The hype behind personalized nutrition

People often like things that are tailored to their needs and preferences. If Netflix has ever recommended a show to you that you loved, you get the attraction. 

Personalized nutrition has the same appeal. It promotes the idea that if you eat a diet customized for you, you can reach your health and fitness goals. Marketing departments and media companies help fuel this hype, as do news articles promoting the benefits of tailored diets. 

Personalized nutrition has a lot of promise. Some evidence indicates that it may help with:

  • Weight loss and maintenance
  • Lower risk of diseases such as heart disease, stroke and type 2 diabetes
  • Improved mood and energy levels
  • Better athletic performance

However, researchers need to study these targeted eating plans in greater depth to confirm these benefits. To date, there’s not a lot of evidence to support the claims of personalized nutrition. Many of the studies have been small and they can’t prove cause and effect. 

Of course, studying personalized nutrition is hard, because it is difficult to control all the factors that can influence someone’s diet and health. It’s challenging to control things such as stress, sleep and physical activity. 

The fact that consumer genetic testing isn’t regulated also complicates precision nutrition. “The Academy of Nutrition and Dietetics posted in a position paper that this approach is ‘not yet ready for routine dietetics practice,’” Hahn said. “More studies are needed.”

Health trackers like CGMs are also controversial when used outside of their specific patient group. “CGMs are a game-changer for those with diabetes, but they are also growing in popularity in the general population where there isn’t a lot of data to support their use,” Hahn said. “With CGM use, non-diabetic people may put undo focus on blood sugars and avoid healthy foods simply because of their glycemic load.”

There can be both good and bad sides to things like fitness trackers and nutrition-tracking apps as well. “Trackers can help people get a glimpse into their activity level or eating habits and find opportunities for change. But they can also lead to obsessive or unhealthy preoccupations with exercise and food,” Hahn said.

Other pitfalls with personalized nutrition

Hahn suggests watching out for these problems when it comes to personalized nutrition:

  • Overstating the link between your genetics and how you respond to food: While genetic factors are important, things like metabolism, lifestyle and overall health status also need to be considered. 
  • Focusing on one perfect diet for each person: The best diet for you is a balanced, nutritious one that you can stick with. Moderation is key when it comes to food. 
  • Excluding or restricting certain foods: Allergies aside, you might not get all the nutrients you need.
  • Expensive plans and devices: DNA testing kits and wearable devices can cost hundreds of dollars and the data you get may not be accurate.
  • Having an unhealthy relationship to food: Since you may need to track your food intake and make changes to what you eat, you might feel anxious or guilty if you go “off plan.” Plans may also make you over-reliant on technology and data to make decisions about your diet.
  • Feeling confused and overwhelmed: Since there’s a lot of conflicting information out there, it’s hard to know which sources to trust. 
  • Isolation: You could feel lonely if your diet keeps you from eating out or socializing with friends.

How general guidelines can support healthy eating

General guidelines on healthy eating are based on scientific evidence and almost everyone can follow them. They are designed to help people be healthy.

Eating a balanced diet that includes a variety of nutrient-rich foods and limited processed foods, sugary drinks and unhealthy fats is good for everyone.

What if you want to try personalized nutrition?

If you want to give personalized nutrition a shot, talk to your health care provider or a registered dietitian. They can help you weigh the benefits and risks and develop a plan that’s safe and effective for you. Be sure to talk to them about your dietary restrictions, food allergies or sensitivities and cultural traditions.

Make sure your plan includes a range of healthy foods — personalized nutrition should complement and fine-tune general guidelines, not replace them. Make gradual, sustainable changes to your diet over time. Don’t forget to focus on other factors that influence good health, such as exercise, sleep and stress management. 

“In most cases, working with a registered dietitian on goals that are suited to you and making small modifications to your diet can make an impact on your overall health,” Hahn said. “Plus, you can work in foods you love. If there was an accurate genetic testing model that said I should not eat chocolate, I think I still would — it’s too delicious.”

The bottom line

Personalized nutrition is centered around the idea that with information about your genetics and health metrics, you can choose the diet that will help you be healthy for life. While the idea is interesting, the research simply isn’t there yet. 

Tailored diets can be useful for avoiding food allergens, treating some chronic health conditions and losing weight. But no single health test or metric tracker can point you toward the perfect diet for you.

If you would like to get more advice on how your diet can help you work toward your health goals, reach out to a dietitian or a health care provider at Banner.

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