This is the era of personalized nutrition. It’s not about figuring out which diet is healthiest for humans anymore. Two people can follow the same diet and have very results. Our genes, environment, health history—even the environment and diet that our parents had before we were even born—all influence how our bodies respond to foods and nutrients.
So how do we go about customizing our diets to fit our unique needs?
In the past, people have proposed basing your diet on your blood type, body shape, or where your ancestors hail from. None of these methods have really stood up to scientific scrutiny.
Blood Type Diet
Ask the Diva: Should People of European Descent Avoid Tropical Fruits?
More recently, as medical technology has advanced, diets based on DNA profiles or microbiome analysis are making the rounds. Some have these are still speculative. Others have some solid science to back them up.
Personalized Nutrition: The Latest on DNA-Based Diets
Just a couple of weeks ago, for example, I talked about a company that has developed and validated an algorithm that can predict your blood sugar response to foods based on an analysis of your intestinal flora.
Can Your Microbiome Reveal Your Ideal Diet?
Knowing what to eat doesn’t always equal eating a healthy diet
In response to that episode one of my colleagues, a registered dietitian named Nancy Teeter, made a very astute observation on my Facebook page: “People can know their perfect diet,” she pointed out, “and still choose not to follow it.”
Many people know what they should be eating. Knowing better doesn’t always lead to doing better.
This is a point that often gets lost in all the excitement about personalized nutrition! I work with people all the time who know full well that the dietary choices they are making are not supporting their health. They know what they should be eating. Knowing better doesn’t always lead to doing better.
I think we often kid ourselves that having more information will result in making better choices, especially if that information is highly specific to us. This is why people sign up for nutrition counseling. But as most nutritionists and dietitians that work with people one-on-one will tell you, very little of their counseling consists of telling people what they should and shouldn’t eat. It ends up being mostly about helping people figure out how to bridge the gap between knowing and doing.
Dieticians help people figure out how to bridge the gap between knowing and doing.
Despite the variances between individuals, there are some universal truths. We don’t have to sequence your DNA or analyze your microbiome to know that foods high in added sugars, fried foods, and highly processed foods are not ideal for the human body. If these foods are still a big part of your diet, it probably makes sense to start eliminating them before spending $500 to find out whether your intestinal bacteria prefer apples to oranges.
If you’re not willing to take these first obvious steps toward a healthier diet, how much good would a personalized dietary prescription based on your genes really do?
A better way to personalize your diet
Although your genetic profile and microbiome might offer a few insights into which approach might be optimal for your biology, I think it’s even more important to optimize for non-biological factors such as your preferences, lifestyle, and priorities.
My friend Jay, for example, struggles with a strong genetic predisposition toward high cholesterol and diabetes. He really wants to manage these issues without medication as much as possible, which means that for him. diet and lifestyle are key.
I think it’s even more important to optimize for non-biological factors such as your preferences, lifestyle, and priorities.
Interestingly, he has had success with two diametrically opposed approaches. A few years ago, when his blood sugar levels were starting to cross the line from pre-diabetic to diabetic, he took the low carb route. He eliminated virtually all sugar and most grains, starchy vegetables, and legumes. His diet was mostly meat, eggs, and vegetables. His weight and blood sugar dropped impressively. But after a year or two, they started to creep back up. Part of the problem was that he found it difficult to sustain a strict low-carb lifestyle long term.
And so, he did a complete U-turn and switched to a vegan diet. Although he still moderates sugar, he now builds his meals around grains and legumes: foods that were mostly off-limits on a low carb diet. This too worked like gangbusters, even though it was pretty much the complete opposite of his previous approach. He lost weight, his cholesterol improved dramatically, and his blood sugar dropped enough to keep him off meds.
Both approaches require giving something up. But over the long haul, Jay was more willing to give up meat and eggs than he was to give up grains.
Which of these approaches would a DNA or microbiome test have suggested for Jay? Who cares? Both approaches worked for his body. But one worked much better for his preferences and lifestyle, making it far more sustainable. Winner, winner, chicken-free dinner.
Three ways to discover the best diet for you
I predict that the science and technology around personalized diets will continue to evolve and become more accurate. But those advancements won’t change what Nancy pointed out: Knowing what diet is best for us doesn’t necessarily make it any easier to follow it.
Here’s are three ways to personalize your diet.
1. Consider the foods you enjoy eating
What sort of foods do you enjoy? Which are you indifferent to? Are your tastes more adventurous or conventional? Some people would be happy to go for the rest of their lives without potatoes as long as they can have steak. Others are exactly the opposite. Some love exotic flavors and ingredients. Others prefer plainer fare. All of these can be important clues to your ideal dietary approach.
That’s not to say that you can never branch out and try new things, but an approach that is completely outside of your comfort zone is going to be hard to sustain for long. As soon as things get busy, we’re likely to revert to our more familiar and comfortable patterns. So let’s start by creating the healthiest possible version of that baseline.
2. Think about how your eating habits make you feel
It’s not just about your taste preferences, though. It’s also important to consider how eating a certain way makes you feel. For example, compare how you feel after eating animal foods, which tend to provide more protein, and how plant-based meals, which are usually higher fiber, make you feel.
It’s not just about your taste preferences. It’s also important to consider how eating a certain way makes you feel.
One day you might have eggs and vegetables for breakfast and top your salad with grilled chicken at lunch. Another day you could have oatmeal with nuts for breakfast and top your salad with garbanzo beans. Then, pay attention to how you feel throughout the day. Do you feel energized or sleepy? How satisfied are you after eating? Does your digestion feel more sluggish or efficient? How soon do you get hungry? Are you cruising through your workouts or feeling underpowered?
3. Contemplate what matters to you
Finally, it’s important to consider what, besides your health, really matters to you. Are you a competitive athlete? An environmental warrior? Is food and cooking an important part of your social and cultural rituals or something to be dispensed with as quickly as possible?
Your diet needs to align with more than your DNA; it also has to be harmonious with your other priorities and values.
The bottom line(s)
I actually have two takeaways for you today:
- The best diet for you is the one you can follow. Our genes and microbiome may hold some clues to which dietary approaches will produce the best biological response, but few of us make dietary decisions based only on our biological needs. A reasonably healthy diet that you can happily and comfortably sustain is better than the biologically “perfect” diet that you can’t or won’t follow.
- The details don’t matter if the basic foundation is missing. You don’t need a microbiome analysis or DNA test to know that cutting back on added sugars, refined carbohydrates, and other highly processed foods and eating more nutritious whole foods will improve your health.