How Stress Affects Blood Sugar: What the Science Really Says

Is your daily stress affecting your blood sugar? The answer may surprise you.

Most conversations about blood sugar focus on food choices and exercise habits. But a growing body of research is finding that psychological stress is a powerful contributor to blood sugar dysfunction. Whether it's the low-grade grind of everyday anxiety (*gestures wildly around at everything going on in the world right now*) or the deep, chronic stress of trauma, what's happening in your nervous system is likely playing a big part in what's going on with your blood sugar.

(And importantly, this research shifts the focus away from body size and eating behavior and toward something that doesn't get nearly enough airtime in mainstream health conversations.)

Here's what the science actually shows and what you can do about it.

The Stress-Blood Sugar Connection: How It Works

When your body perceives a threat (whether that is physical threat like a car accident or an emotional/psychological threat like emotional abuse or a job change) it activates the hypothalamic-pituitary-adrenal (HPA) axis, triggering the release of stress hormones like cortisol and adrenaline. These hormones are designed to give you a burst of energy in a crisis. To do that, they signal your liver to release glucose into the bloodstream because glucose = energy.

In short: stress literally raises your blood sugar.

This stress response is good! We need it for survival. If we are being chased by a mountain lion, we need a lot of glucose in the blood. It is a helpful and necessary response to what is happening around us or within us.

For occasional stressors, this is a normal, healthy response. But when stress becomes chronic, the system stays activated. Cortisol remains elevated, glucose stays high, and over time, your cells begin to resist insulin's signals. That process, called insulin resistance, is a key driver of type 2 diabetes.

Decades of peer-reviewed evidence, spanning decades and tens of thousands of participants, supports this theory.

What the Research Shows

Everyday Stress Significantly Raises Diabetes Risk

A landmark 12-year longitudinal study published in 2017 by Harris and colleagues (1) followed nearly 13,000 Australian women born between 1946 and 1951, tracking their perceived stress levels and health outcomes across multiple survey waves. The researchers found that moderate to high stress levels were associated with a more than twofold increase in the odds of developing type 2 diabetes three years later.

What makes this study particularly striking is what the researchers found when they dug deeper into how stress was producing this effect. When the direct and indirect effects of perceived stress on diabetes were separated out, traditional risk factors — including hypertension, physical activity, body mass index, smoking, and diet quality — explained only 10 to 20% of the excess variation in diabetes risk linked to stress.

In other words, stress appears to raise diabetes risk independent of these factors. Stress itself is raising blood sugar through its own biological pathways — pathways that have nothing to do with what someone eats or their body size.

This is a significant finding. It means that focusing diabetes prevention exclusively on food, weight, or exercise misses the majority of what stress is actually doing to the body.

Chronic Traumatic Stress Has Lasting Metabolic Consequences

If everyday stress has this kind of power, what happens to people carrying the weight of sustained trauma? The answer comes from a large Veterans Health Administration study published in 2019 by Scherrer and colleagues (2), which examined medical records from nearly 1,600 patients diagnosed with PTSD.

Researchers found that patients who achieved a clinically meaningful reduction in PTSD symptoms — defined as a 20-point or greater decrease on a standardized PTSD checklist — were 49% less likely to develop type 2 diabetes compared to those whose symptoms did not meaningfully improve.

Read that again: reducing stress-related symptoms was associated with nearly half the diabetes risk.

The study controlled for a wide range of factors, including hypertension, depression, and substance use, meaning the association held up independent of those factors.

Perhaps most importantly, the protective effect wasn't limited to patients who pursued formal psychotherapy. Whether symptom improvement came from treatment or another mechanism, the metabolic benefit was significant. This suggests the body's stress load itself (not any particular behavior) is what matters most for blood sugar.

Why Most People Don't Connect These Dots

The stress-blood sugar link is consistently under-appreciated for a few reasons.

The effect isn't always immediate. Unlike an acute stressor and its quick glucose spike, chronic stress works slowly. The impact accumulates over months and years, making it easy to miss the connection.

Stress is normalized. We live in a culture that treats chronic stress as a baseline condition rather than a health risk; something to push through, not address.

Health conversations overemphasize individual behaviors. Clinical guidelines and mainstream health media tend to center diabetes risk almost entirely on food choices, exercise, and body weight... This not only leaves the stress piece out, but can itself become a source of shame and stress for people, particularly those in eating disorder recovery or in larger bodies navigating a weight-centric medical system.

Scherrer and colleagues made a related point directly: type 2 diabetes continues to rise despite interventions built around traditional risk factors. There is, they wrote, a clear need to identify additional pathways for chronic disease prevention. Stress represents one of the most meaningful ones identified to date.

Who Is Most Affected?

Chronic stress touches virtually everyone, but some people carry a disproportionate burden:

• People with PTSD or trauma histories face significantly elevated metabolic risk, as the data from the second study show, and the research suggests that treating trauma is also, in a real sense, caring for metabolic health.

• Women in midlife, based on the first study, showed a strong dose-response relationship between perceived stress and diabetes onset.

• People in high-demand jobs or caregiving roles, where chronic low-grade stress is constant and genuine rest is rare.

• People in eating disorder recovery, for whom diet culture messaging around blood sugar can itself be a stressor, and for whom the stress of diet cycling, food fears, and body shame may have been quietly affecting metabolic health all along.

• People who experience weight stigma, including in healthcare settings, where stress from stigmatizing encounters is documented and real, and where this stress has its own physiological consequences.

What Actually Helps

The hopeful message in this research is real: reducing stress has measurable benefits, whether you have type 2 diabetes, prediabetes or want to prevent them. This isn't about achieving some perfect, stress-free state. It's about meaningfully lowering chronic activation in ways that feel sustainable and accessible to you.

Evidence-based approaches that support the nervous system and HPA axis regulation include:

• Trauma-focused therapy (EMDR, IFS): the Scherrer study found that meaningful PTSD symptom reduction was directly tied to lower diabetes incidence.

• Mindfulness-based stress reduction (MBSR): shown to lower cortisol and support insulin sensitivity.

• Joyful, non-compulsory movement: not as a compensatory tool, but as a genuine nervous system regulator when it feels good and accessible.

• Quality sleep: poor sleep activates the same stress pathways that elevate blood glucose

• Social support and connection: chronic loneliness is itself a physiological stressor.

• Setting limits on diet culture content and messaging: for people in ED recovery especially, reducing exposure to triggering food and body content is a compassionate and radical act.

• Somatic and sensory nervous system tools: small, accessible practices can meaningfully lower the body's stress response between therapy sessions or on hard days. This includes the breath (box breathing or making your exhale longer than your inhale), splashing cold water on your face, grounding exercises like the 5-4-3-2-1 sensory method, and weighted blankets. Weighted blankets use deep pressure stimulation to calm the nervous system, similar to the science behind swaddling. Treat yourself like a lil baby!

It's worth saying clearly: you do not have to pursue weight loss, restrict your eating, or change your body size to support your metabolic health. The research highlighted here points toward nervous system care as a meaningful, underutilized path.

The Bottom Line

The evidence is clear: stress and blood sugar are deeply, biologically connected. Chronic stress (whether from daily life or unresolved trauma) raises cortisol, elevates glucose, and over time, increases the risk of developing type 2 diabetes through mechanisms that largely bypass the factors we usually talk about.

This matters for everyone, and especially for those who have been told their health is about their weight or their diet choices. It isn't that simple and it's never the whole story.

Taking care of your nervous system is taking care of your metabolic health. That's not a soft message — it's what the science shows.

Ready to approach your diabetes care without the diet culture baggage? Diabetes, Liberated is an anti-diet digital workbook designed to help you thrive with Type 2 Diabetes — bridging the gap between traditional diabetes education and modern weight-inclusive care. Because you deserve support that actually respects your body.

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References:

1. Harris ML, et al. (2017). Stress increases the risk of type 2 diabetes onset in women: A 12-year longitudinal study using causal modelling. PLOS ONE. https://doi.org/10.1371/journal.pone.0172126

2. Scherrer JF, et al. (2019). Association Between Clinically Meaningful Posttraumatic Stress Disorder Improvement and Risk of Type 2 Diabetes. JAMA Psychiatry, 76(11):1159–1166. https://doi.org/10.1001/jamapsychiatry.2019.2096