The Science Behind Mindset and Health: Why Your Thoughts Matter More Than You Think

Genetics, DNA, physiology, etc., are always considered real science, but things like mindset are often dubbed "woo woo" and not associated with scientific findings.

I can't tell you how many times I've heard someone say, "Mindset is just woo woo stuff."

You're not alone if you've ever thought (or heard) a version of that phrase. Many health professionals and clients tend to view mindset as a soft, less tangible part of the health and fitness equation. It's easy to believe that genetics, hormones, and physiology are the real science, while things like beliefs, expectations, and thought patterns are secondary — or worse, irrelevant.

But science says otherwise. And, if that were the case, I wouldn't be doing what I do, which is teaching folks how to harness growth mindsets to cultivate long-term behavior change.

When it comes to health and fitness, we know they both play a role. But what happens when we put them up against each other? Which one makes the greater impact?

In this post, I'm breaking down the actual research behind the connection between mindset and health, illustrating how deeply your mental framework can influence everything from hunger hormones to fitness outcomes. If you're a health or fitness coach struggling to understand (and explain) the evidence-based impact of mindset, this one's for you.

What Is Mindset, Really?

Let's start by defining what I mean by mindset. Many people who are new to hearing or learning about mindset theory think it's just positive self-talk or having a positive attitude, but mindset is so much more than that.

In psychological terms, mindset refers to the collection of beliefs, thoughts, and assumptions we hold about ourselves, the world, and what we're capable of.

Our mindset influences how we interpret events, how we respond to challenges, and how likely we are to stay consistent with habits over time. It's not just a buzzword — it's a measurable psychological construct that plays a significant role in health outcomes.

When it comes to mindset and behavior change, we typically refer to people having either a growth or a fixed mindset.

Something that's essential for you to know is that mindset is not black and white. Some people have a growth mindset about some aspects of their lives and a fixed mindset about others. And they can also fall somewhere in between.

For more information, you can check out my blog post on mindset and what it takes to be a true mindset coach.

Can a Healthy Mindset Overpower Genetics?

Mindset research got popularized in the early 1970s by Carol Dweck, and researchers have been looking more and more at the connections between mindset, behavior, genetics, health, etc., so this is, in a way, a newish area of study.

However, what we know thanks to genetic and mindset research for health and fitness is that certain gene variants are associated* with obesity (Lamiquiz-Moneo et al., 2019), and your mindset about health risk factors is associated* with outcomes and effectiveness of treatment (Crum et al., 2017).

*Note: When we talk about associations in research or say, "research shows," that doesn't mean "proof." Research does not prove things. That's not how science works.

Mindset vs. Genetics: A Study on Perceived Risk

One of the most compelling pieces of evidence for the power of mindset comes from a study conducted by Turnwald et al. (2019). Researchers tested how learning about fake genetic results affected a person's capacity for exercise and likelihood to overeat.

Participants were randomized into groups. They (falsely) told the first group that they carried a gene that makes them have lower endurance and find prolonged exercise difficult. They (falsely) told the second group that they carried a gene that makes it easier for them to feel full and less likely to overeat.

Even though their DNA hadn't changed, their bodies responded as if it had.

Being told about these fake genetic results predicted people's endurance, oxygen uptake, and lung capacity (it was significantly lower than it was before they learned about their "genetic results").

The findings also impacted the fullness and ghrelin (hunger hormone) in participants of group two. Researchers found fullness was significantly higher and ghrelin was significantly lower than before they told participants about their "genetic results."

But wait, there's more!

People who believed they had genetic disadvantages or advantages (but didn't) displayed more negative physical impacts compared to those who ACTUALLY have these genetic variants (aka not fake).

Researchers said, "Effects of perceived genetic risk on outcomes were greater than the effects associated with actual genetic risk."

What does this mean? Believing you're biologically limited can cause your body to behave like you are.

This is a textbook example of what researchers call a self-fulfilling prophecy. The expectations we hold can directly impact our biology.

Researchers state: "Mindset seems to play an equal or even greater role than does our DNA in shaping some of our bodies' reactions to diet and exercise."

It's essential that you, as a fitness coach, be on the lookout for these types of belief systems in your clients because they lead to a fixed mindset and negative self-talk, both of which can prevent them from improving their health and well-being.

How Mindset Shapes Health Outcomes

Placebo research has long shown that our expectations can shape outcomes. People who believe they're receiving pain medication often feel less pain, even when they're given a sugar pill (aka placebo). But this doesn't just apply to clinical medicine.

Similar effects have been repeatedly observed in the context of health and fitness:

• In a study by Crum and Langer (2007), hotel room attendants who were told their work met the Surgeon General's recommendations for physical activity showed improved health markers even though their actual workload didn't change.
• In Crum et al. (2011), participants consumed milkshakes with identical nutritional profiles. Those who believed they were drinking an indulgent shake showed greater reductions in ghrelin (a hunger hormone) than those who thought the shake was diet-friendly.

Again, perception changed the physiological outcome. Mindset doesn't just influence motivation — it impacts metabolism, hormonal response, and more.

Why Perception Matters for Health Coaches

As a health coach, it's easy to get wrapped up in creating the perfect protocols for your clients. What to eat, how to move, what to track. And while those things matter, you miss a critical part of the puzzle if you ignore mindset.

Here are just a few reasons why your clients' thoughts and beliefs matter just as much as (if not more than) their macros:

• If they believe they're genetically destined to fail, they'll behave in ways that fulfill that narrative.
• If they expect their workouts to be ineffective, their performance and recovery may actually suffer.
• If they think they "just don't have self-control," they may make choices that reflect that belief.

This isn't about ignoring physiology. It's about recognizing that their health and mindset are intertwined, and working on one without the other is incomplete coaching.

Seeing this gap in the fitness coaching space is exactly why I created the Health Mindset Coaching Certification, which teaches coaches how to create mindset shifts within their clients to stop all-or-nothing thinking, put an end to self-sabotage, and develop more self-control, so they can increase client motivation and see better results.

I have five FREE lessons for you if you want to start learning about mindset today.

How to Talk to Clients About Mindset

A big part of your job is helping clients build belief. Not delusion, but grounded confidence in their ability to change. Teaching your clients about mindset is more than having them do some positive self-talk.

Here are ways to shift their belief systems to be more growth mindset oriented:

1. Swap "I'm bad at this" with "I'm learning how to do this."

Few of us are born good at things, and if they are doing something they have never done before (like tracking macros or prioritizing their health and well-being overall), your clients likely WILL struggle. Self-criticism won't help them get results any faster. This subtle shift promotes a growth mindset and helps reduce the shame spiral that often leads to giving up.

2. Emphasize effort and process over outcome.

Celebrate consistency and intention, not just results. Remind your clients that mindset shifts often come before they see physical changes. It's also essential to emphasize that cultivating a growth mindset is the key to long-term health benefits since that is the only way to create true behavior change. If they don't improve their mindsets, then they will likely end up back where they started.

3. Teach the science.

When clients understand that mindset is evidence-based — not woo woo — it builds buy-in and helps increase motivation. Your clients will stop seeing belief as fluff and start seeing it as a tool.

And if you aren't sure which studies are best when looking into evidence-based coaching practices, check out this blog post, which teaches you how to identify good research studies.

Mindset and Physiology Have a Significant Effect on Each Other

One of the most empowering truths you can teach a client about mindset and their health is that it's a two-way street. Yes, thoughts influence biology, but biology also influences thoughts. This is why:

• Movement boosts mood and improves cognitive flexibility.
• Nourishing food affects energy, sleep, and mental clarity.
• Consistent behaviors reinforce positive self-image.

Helping your clients understand this loop means giving them more control. When they feel stuck, they can act their way into a better mindset — or think their way into a better behavior. It's a good way to help them feel more in control of their success with their health.

Mindset Work Is Evidence-Based Coaching

Too often, coaches treat mindset like an "extra" — something to sprinkle in between meal plans and workout splits. But mindset work isn't extra. It's foundational to your client's success and to actual behavior change!

If your client doesn't believe change is possible, if they think they're broken or genetically doomed, if they view setbacks as proof of failure, then it doesn't matter how perfect your program is. The beliefs underneath will continue to derail their progress.

By incorporating mindset work into your coaching practice, you:

• Increase adherence
• Improve long-term outcomes
• Create more empowered, resilient clients

And now, you have the science to back it up.

When you dig deeper into mindset, beliefs, values, and mindfulness, you become a coach who transforms lives, not just bodies.

If you want to improve your coaching skills and feel confident guiding real, lasting behavior change, start with my 5 FREE Mindset and Behavior Change Lessons.

These bite-sized trainings are packed with tools you can start using right away to help you retain clients longer, confidently help clients work through mindset barriers, and make your coaching more profitable.

The Health Mindset Coaching Certification is the best way to help your clients improve their mindset and create lasting behavior change. This 14-week program for health and fitness professionals equips you with the skills you need to help your clients end self-sabotage, break through mindset barriers, and make behavior changes for good.

You'll learn research-backed methods that will help your clients embrace a growth mindset and create lasting behavior change.

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IG:@coachkaseyjo@healthmindsetcert

Sources

Crum, A. J., Akinola, M., Martin, A., & Fath, S. (2017). The role of stress mindset in shaping cognitive, emotional, and physiological responses to challenging and threatening stress. Anxiety, stress, and coping, 30(4), 379–395. https://doi.org/10.1080/10615806.2016.1275585

Crum, A. J., Corbin, W. R., Brownell, K. D., & Salovey, P. (2011). Mind over milkshakes: mindsets, not just nutrients, determine ghrelin response. Health psychology : official journal of the Division of Health Psychology, American Psychological Association, 30(4), 424–431. https://doi.org/10.1037/a0023467

Crum, A. J., & Langer, E. J. (2007). Mind-set matters: exercise and the placebo effect. Psychological science, 18(2), 165–171. https://doi.org/10.1111/j.1467-9280.2007.01867.x

Lamiquiz-Moneo, I., Mateo-Gallego, R., Bea, A.M. et al. Genetic predictors of weight loss in overweight and obese subjects. Sci Rep 9, 10770 (2019). https://doi.org/10.1038/s41598-019-47283-5