Researchers studied over 117,000 Spanish workers to understand what causes insulin resistance—a condition where your body struggles to use insulin properly, leading to diabetes and heart problems. They found that people who were physically inactive, socially isolated, smoked, ate poorly, were male, older, or had lower income were more likely to have insulin resistance. The biggest risk factors were not exercising and feeling lonely or unsupported. This suggests that workplaces should pay attention to both physical activity and workers’ social connections to help prevent serious health problems.

The Quick Take

  • What they studied: What lifestyle habits, personal circumstances, and social connections are linked to insulin resistance—a hidden condition where your body can’t use insulin effectively.
  • Who participated: 117,298 workers from health clinics across Spain. The group included people of different ages, income levels, and backgrounds who work in various jobs.
  • Key finding: Not exercising was the strongest risk factor (6-10 times more likely to have insulin problems), followed by feeling socially isolated or unsupported (2-4 times more likely). Men, older workers, smokers, and those eating poorly also had higher risk.
  • What it means for you: If you work, paying attention to exercise, building social connections, quitting smoking, and eating better Mediterranean-style foods may help protect your body’s ability to use insulin properly. However, this study shows connections, not proof of cause-and-effect, so talk to your doctor about your personal risk.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot in time of 117,298 Spanish workers and looked at their characteristics all at once. They collected information about workers’ age, sex, income level, exercise habits, diet, smoking, and how socially connected they felt. They also measured blood sugar-related markers and body measurements like weight and waist size.

The researchers used three different mathematical formulas to calculate insulin resistance risk based on blood tests and body measurements. These formulas are like different ways of scoring how well your body is handling insulin. They then used statistical analysis to see which factors were most strongly linked to higher insulin resistance scores, while accounting for other factors that might affect the results.

This approach is important because it looks at a very large, real-world group of working people rather than a small laboratory study. By studying actual workers in their normal lives, the findings are more relevant to everyday people. The researchers also looked at social isolation, which hasn’t been studied much before in relation to insulin resistance, making this research fill an important gap in our understanding.

The study’s strengths include its very large sample size (over 117,000 people), standardized measurements taken by health professionals, and consistent results across three different insulin resistance measures. However, because it’s a snapshot study rather than following people over time, we can’t be certain that these factors actually cause insulin resistance—only that they’re connected. The study was conducted in Spain, so results may not apply equally to all populations worldwide.

What the Results Show

The research found that physical inactivity was the strongest risk factor for insulin resistance. People who didn’t exercise regularly were 6 to 10 times more likely to have high insulin resistance scores compared to active people. This was true across all three measurement methods used in the study.

Social isolation and low social support were the second-strongest risk factors. People who felt lonely or unsupported were 2 to 4 times more likely to have insulin resistance. This was a surprising finding because social connection hasn’t been studied much in relation to insulin resistance before.

Other important risk factors included smoking, not following a Mediterranean diet (which emphasizes vegetables, fish, and olive oil), being male, getting older, and having lower income or social class. All of these factors were independently linked to higher insulin resistance, meaning each one mattered even when accounting for the others.

Interestingly, the patterns were consistent across all three different ways of measuring insulin resistance, suggesting these findings are reliable and not dependent on which measurement method is used.

The study found that the combination of multiple risk factors was particularly concerning. Workers who had several of these risk factors together—such as being inactive, socially isolated, and smoking—had even higher insulin resistance scores than those with just one risk factor. The researchers also noted that socioeconomic factors (income and social class) played a significant role, suggesting that workplace and economic conditions matter for metabolic health.

Previous research has established that physical inactivity, poor diet, smoking, and older age increase insulin resistance risk. This study confirms those findings in a large working population. However, the strong association with social isolation and low social support is relatively new to the insulin resistance research. While loneliness has been linked to other health problems like heart disease and depression, this study provides substantial evidence that it’s also connected to insulin resistance, suggesting social health is as important as physical health for metabolic wellness.

This study shows associations but cannot prove that these factors cause insulin resistance—only that they’re connected. Because it’s a snapshot rather than following people over time, we don’t know if these factors lead to insulin resistance or if people with insulin resistance make different lifestyle choices. The study was conducted in Spain with Spanish workers, so the results may not apply equally to other countries or populations with different cultures and healthcare systems. Additionally, the study relied on self-reported information for some factors like diet and exercise, which may not be completely accurate.

The Bottom Line

Based on this research, workers should prioritize regular physical activity (moderate to high confidence), maintain social connections and community involvement (moderate confidence), follow a Mediterranean-style diet rich in vegetables and fish (moderate confidence), and avoid smoking (high confidence). Workplaces should consider implementing programs that encourage exercise, foster social connection among workers, and support mental health. However, these recommendations should be discussed with your healthcare provider, especially if you have existing health conditions.

This research is relevant to all working adults, particularly those who are sedentary, socially isolated, smoke, or have lower income. Men and older workers should pay special attention. People with family history of diabetes or heart disease should be especially interested. However, this research doesn’t apply to children or non-working populations in the same way. If you have existing diabetes or heart disease, consult your doctor before making major lifestyle changes.

Physical activity improvements may show benefits in blood sugar control within 2-4 weeks, though significant changes in insulin resistance typically take 8-12 weeks of consistent exercise. Social connection improvements may take longer to show metabolic benefits, potentially 3-6 months. Diet changes usually show measurable improvements in 4-8 weeks. These are general timelines; individual results vary significantly.

Want to Apply This Research?

  • Track weekly exercise minutes (aim for 150+ minutes of moderate activity), daily social interactions (number of meaningful conversations or social activities), and Mediterranean diet adherence (servings of vegetables, fish, and olive oil used). Monitor these three factors weekly to identify patterns.
  • Set a specific, achievable exercise goal (e.g., 30-minute walks 5 days per week), schedule regular social activities (e.g., weekly coffee with friends or group fitness classes), and plan Mediterranean meals for the week ahead. Use the app to log these activities and receive reminders.
  • Create a dashboard showing your progress on exercise, social connection, and diet adherence over 12 weeks. Set monthly goals that gradually increase activity and social engagement. If possible, share progress with friends or family for accountability. Consider periodic blood work (with your doctor) to track actual insulin resistance markers over time.

This research shows associations between lifestyle factors and insulin resistance but does not prove cause-and-effect relationships. The findings are based on a Spanish working population and may not apply equally to all groups. This information is for educational purposes only and should not replace professional medical advice. If you have concerns about insulin resistance, diabetes risk, or metabolic health, consult with your healthcare provider or a registered dietitian. Before starting any new exercise program or making significant dietary changes, especially if you have existing health conditions, speak with your doctor. This study does not constitute medical diagnosis or treatment recommendations.