Is Insulin Resistance Quietly Undermining Your Leadership Team?

Corporate Wellness · LaVera J. Forbes, PhD, MS, CHN

Let me ask you something that your last employee wellness survey almost certainly did not. How many of your senior leaders are sleeping seven or eight hours and still dragging themselves through afternoon meetings on coffee? How many have been quietly gaining weight around the midsection despite doing what they've always done? How many have mentioned, offhandedly, that their thinking feels slower — that words come less easily, that decisions that used to feel clear now feel murky?

You probably attributed it to stress. So did they. Often, so did their doctors.

But here is what the research increasingly suggests: those three experiences — fatigue that sleep doesn't fix, stubborn abdominal weight, and cognitive dullness — aren't always just the cost of a demanding career. They can be signs of insulin resistance. And national survey data (NHANES) suggest that roughly 4 in 10 US adults without diabetes have insulin resistance (Parcha et al., 2022; NHANES trends analysis, J Clin Med, 2025), and most have never been tested for it.

If national figures hold, several of the leaders around your table may have insulin resistance — and not know it.

What insulin resistance can do to a high-performing brain

Here is the mechanism, in plain language. Every time a person eats, blood sugar rises, and the pancreas releases insulin — a hormone whose job is to help move glucose into the cells, where it becomes fuel. In a healthy metabolism, this process is elegant and self-correcting. In insulin resistance, the cells stop responding properly to insulin's signal, and the pancreas has to work harder to keep blood sugar in range.

The brain is one of the most metabolically demanding organs in the body, using roughly 20 percent of the body's energy while making up only about 2 percent of its weight (Raichle & Gusnard, PNAS, 2002). Research links insulin resistance to changes in brain energy use and blood-vessel health, and to poorer memory and attention (Arnold et al., Nature Reviews Neurology, 2018).

At the level of day-to-day leadership, that can look like this: difficulty sustaining focus during complex problem-solving; slower retrieval of names, words, and data the person knows perfectly well; lower tolerance for ambiguity and more emotional reactivity under pressure; and a persistent fatigue that sits beneath everything, no matter how much sleep the person gets.

In any employee, these symptoms can mean reduced output. In a senior leader, they can affect judgment at the moments that matter most.

Why the standard health screening can miss it

This is the part that should get your attention. The annual health screening many organizations provide — the one that checks HbA1c and fasting glucose — is good at catching diabetes and prediabetes, but it doesn't measure insulin. That means insulin resistance can progress for years before those numbers change. In one long-term study, people who later developed type 2 diabetes already showed lower insulin sensitivity more than a decade before their diagnosis (Tabák et al., The Lancet, 2009).

Here is why. When insulin resistance first develops, the pancreas compensates by producing more insulin. Blood glucose stays in the normal range — because the pancreas is working overtime to hold it there. The HbA1c looks fine. The fasting glucose looks fine. And the person hears the words that millions of people have heard: "Everything looks good. Keep an eye on your stress levels."

What the standard panel usually does not include is a fasting insulin test — one useful window into metabolic function. Nor does it include HOMA-IR, a calculated estimate that uses both fasting glucose and fasting insulin to gauge the degree of insulin resistance. These tests exist. They are accessible. They simply aren't part of most routine panels, so they are rarely ordered unless someone asks — and the earlier the problem is found, the more options there are for addressing it through diet and lifestyle.

Even the screening that does exist misses many people. One national analysis found the 2021 US screening criteria identify only about 6 in 10 adults with prediabetes or undiagnosed diabetes (O'Brien et al., American Journal of Preventive Medicine, 2023). And researchers estimate that nearly 4 in 10 US adults have prediabetes, and about 8 in 10 of them don't know it (Xia et al., Diabetes Care, 2022). These are not outliers. Statistically speaking, they are people sitting in your leadership meetings right now — at every level of your organization.

And here is the part that surprises even many medically informed executives: even when a blood test comes back flagged, and the words "insulin resistance" or "prediabetes" are said out loud, a typical appointment has very little time for a detailed, step-by-step lifestyle plan, and most doctors receive very little training in nutrition or lifestyle medicine. Your leaders may be told to watch their diet, lose weight, and come back in six months. What many still need is practical, sustained support in making the specific nutrition and lifestyle changes the research supports. That gap is precisely what this program is designed to fill — working alongside each person's own physician, not in place of them.

What this costs an organization — beyond the obvious

The direct healthcare costs associated with insulin resistance and its downstream conditions are well documented: type 2 diabetes, some cancers, dementia, cardiovascular disease, and fatty liver disease all carry significant weight in any benefits analysis.

But the costs that rarely appear in a CFO's report are the ones I find most compelling for corporate leadership specifically. The cost of a senior leader making a major acquisition decision while running on fumes. The cost of a director whose emotional regulation is disrupted by blood sugar swings, making them harder to work with, and who doesn't know why. The cost of losing a key manager in their forties to a cardiovascular event — not because they didn't care about their health, but because nobody looked at the full picture early enough.

These costs are real. They are happening inside organizations right now. And with the right information and support, many of them are preventable.

What a properly structured corporate wellness program can do

I want to be precise about what I mean by "the right support," because this matters enormously. I am not talking about a wellness portal, a meditation app, or a one-size-fits-all nutrition handout. I am talking about a structured, confidential, individual metabolic program that starts by helping each participant discuss the right tests with their own healthcare provider — and then delivers a personalized, science-informed plan to address what those tests reveal.

The research on this kind of lifestyle approach is genuinely encouraging. Clinical trials show that lifestyle changes such as meal timing, weight loss, and exercise can significantly improve insulin sensitivity within weeks, and that a meaningful share of people with prediabetes return to normal glucose levels. In other words, insulin resistance can often be reversed. In a small Cell Metabolism study, five weeks of early time-restricted eating improved insulin sensitivity in men with prediabetes (Sutton et al., 2018). In a large German trial, 43% of people with prediabetes who lost at least 5% of their body weight returned to normal glucose regulation (PLIS, Lancet Diabetes & Endocrinology, 2023).

A note on safety for participants: Anyone who takes medication for diabetes (especially insulin or a sulfonylurea such as glipizide, glyburide, or glimepiride) or for blood pressure should talk with their doctor before trying fasting or time-restricted eating, or adding supplements such as berberine. Combining them can cause low blood sugar, and some supplements interact with medications. No one should stop or change a prescribed medication on their own, and the program is built around that.

After I made targeted changes, all my labs returned to normal, and I have since helped many others make similar changes alongside their physicians. I hold a PhD in Mind-Body Medicine and am a certified holistic nutritionist. I am also a retired senior executive. I know what these tests can show and which changes the research supports. And I built a corporate program specifically because I kept asking myself: how many leadership teams — executives, directors, managers — are quietly operating below their potential right now, for a reason that nobody has named?

If you are a CHRO, a Chief Medical Officer, or a CEO who has ever watched an otherwise exceptional leader struggle with the kind of persistent fatigue and mental fog that no amount of stress-management advice seems to touch — this conversation is for you.

drlavera@drlavera.com

Sources

  1. Parcha V, et al. Insulin Resistance and Cardiometabolic Risk Profile Among Nondiabetic American Young Adults: Insights From NHANES. Journal of Clinical Endocrinology & Metabolism. 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC8684535/
  2. Trends in Hyperinsulinemia and Insulin Resistance Among Nondiabetic US Adults, NHANES, 1999–2018. Journal of Clinical Medicine. 2025;14(9):3215. https://pmc.ncbi.nlm.nih.gov/articles/PMC11601873/
  3. Raichle ME, Gusnard DA. Appraising the brain's energy budget. PNAS. 2002. https://www.pnas.org/doi/10.1073/pnas.172399499
  4. Arnold SE, et al. Brain insulin resistance in type 2 diabetes and Alzheimer disease: concepts and conundrums. Nature Reviews Neurology. 2018. https://pmc.ncbi.nlm.nih.gov/articles/PMC6098968/
  5. Tabák AG, et al. Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes (Whitehall II). The Lancet. 2009. https://pubmed.ncbi.nlm.nih.gov/19515410/
  6. O'Brien MJ, et al. Screening for Prediabetes and Diabetes: Clinical Performance and Implications for Health Equity. American Journal of Preventive Medicine. 2023. https://pubmed.ncbi.nlm.nih.gov/37171231/
  7. Xia PF, et al. Trends in Prevalence and Awareness of Prediabetes Among Adults in the U.S., 2005–2020. Diabetes Care. 2022;45(2):e21–e23. doi:10.2337/dc21-2100. https://pubmed.ncbi.nlm.nih.gov/34872984/
  8. Sutton EF, et al. Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metabolism. 2018. https://www.cell.com/cell-metabolism/fulltext/S1550-4131(18)30253-5
  9. Prediabetes Lifestyle Intervention Study (PLIS) post-hoc analysis. The Lancet Diabetes & Endocrinology. 2023. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(23)00235-8/abstract

This article is for educational purposes and isn't medical advice. Talk with your healthcare provider before changing your diet, exercise, or medications.