Why do so many of my skinny asian girlfriends have prediabetes?

When I came back from living abroad for six months and went on our annual girls’ trip, I expected long dinners, laughter, and late-night heart-to-hearts. What I didn’t expect was that three out of five of my Asian girlfriends—women I’ve known for years—would break the news that they had prediabetes.

These women are all size 2–4. They run, they do yoga and pilates, they eat their veggies. They’re not the picture of “unhealthy.” So how is it possible that half of them are already being told they’re on the road to diabetes?

The short answer: BMI and insulin resistance look different in Asians.

The “Skinny-Fat” Problem

Most of us grew up hearing that if your body mass index (BMI) is under 25, you’re “normal weight.” That’s the standard cutoff used in the U.S. and Europe. But here’s the catch: for Asian populations, those cutoffs don’t tell the full story.

Research shows that Asians carry a higher percentage of body fat and more visceral fat (the fat that sits deep around the organs) at the same BMI compared to white populations [1–4]. That means an Asian woman with a BMI of 22 may have the same metabolic risk as a white woman with a BMI of 27.

This phenomenon—sometimes called “skinny-fat”—explains why outwardly slim people can still have metabolic syndrome, insulin resistance, and higher diabetes risk [1,5–7].

It’s not that they’re secretly overeating or not exercising enough. It’s that their body composition—how fat is distributed and how much visceral fat accumulates—creates metabolic risk even when their weight looks “normal.”

Why the Standard BMI Cutoffs Don’t Work for Asians

Because of this difference in body composition, major organizations like the World Health Organization (WHO) and the American Heart Association (AHA) have recommended lower BMI cutoffs for Asian individuals:

• Overweight: BMI ≥23 kg/m² (instead of ≥25)
• Obesity: BMI ≥27.5 kg/m² (instead of ≥30)

These numbers aren’t arbitrary—they’re based on decades of evidence showing that Asians develop hypertension, type 2 diabetes, and cardiovascular disease at much lower BMIs than white populations [1–4].

Think about it this way: if your doctor is still using the “standard” BMI thresholds, they might not flag you for screening until you’re already in trouble. That’s exactly what happened to my girlfriends—who were told their glucose was “a little high” only after prediabetes had already developed.

Diabetes Risk at Lower BMIs

This isn’t just a small bump in risk—it’s a dramatic difference. South Asian and Filipino adults can have 5–8 times the prevalence of diabetes compared to white adults at the same BMI [1,8–9].

In fact, a 2022 study found that Asian Americans at a “healthy” BMI (18.5–23 kg/m²) already had higher rates of prediabetes and diabetes than white adults in the overweight or obese categories [8].

And for Asian women specifically, the American Heart Association highlights that polycystic ovary syndrome (PCOS) and insulin resistance occur at lower BMI in Asian women, increasing their risk of both diabetes and cardiovascular disease [1,10].

Who Is Most Affected?

While increased risk starts early, the highest prevalence of prediabetes and diabetes is seen in middle-aged Asians (ages 45–64) [8]. But studies also show that young Asian adults already show higher insulin resistance compared to their white peers [4].

That means the risk builds slowly, often silently. And because outward weight doesn’t look concerning, people often miss the early signs. By the time prediabetes is diagnosed, the window for prevention has narrowed.

A Case Study in Misclassification

Here’s the problem: if you’re Asian and your BMI is 23, a standard U.S. chart will label you “normal.” But according to the AHA, WHO, and ADA, you’re already in the overweight category for Asian populations [2,3,9].

That mismatch leads to thousands of people being overlooked. A doctor might not screen you until years later, even though the risk is already real. By the time glucose abnormalities show up in routine labs, insulin resistance may have been present for a decade.

This is why Asian Americans, despite being one of the fastest-growing ethnic groups in the U.S., remain under-screened and underdiagnosed when it comes to diabetes [3,9].

Why Does This Happen Biologically?

1. Higher Body Fat Percentage – Asians have more fat mass for the same BMI compared to whites [5–6].
2. Visceral Fat Distribution – Fat tends to deposit around the organs rather than just under the skin. This type of fat is highly inflammatory and disrupts insulin signaling [1,6–7].
3. Insulin Resistance at Lower BMI – Studies show that insulin sensitivity is lower in Asians even before overt obesity develops [1,7].
4. Hormonal Factors in Women – PCOS and perimenopausal changes in Asian women interact with insulin resistance, worsening metabolic risk earlier in life [1,10].

Put simply, BMI doesn’t measure fat distribution—and in Asians, it underestimates risk.

The Silent Nature of Prediabetes

Prediabetes often has no symptoms. You don’t feel your pancreas struggling. You don’t notice insulin quietly rising in the background. By the time fasting glucose or A1c creeps up, you’ve likely been on that trajectory for years.

That’s why so many of my girlfriends were shocked. On the outside, nothing looked wrong. Inside, insulin resistance was quietly building until it tipped over into prediabetes.

What to Do: Practical Recommendations

1. Get Labs Done Earlier

• The USPSTF recommends diabetes screening in Asian Americans starting at a BMI ≥23 kg/m² [10].
• Ask for: fasting glucose, HbA1c, and/or a 2-hour oral glucose tolerance test.
• If you’re 35 or older and have risk factors (family history, PCOS, central weight gain), don’t wait until 45—the earlier, the better.

2. Know the Risk Thresholds

• BMI ≥23: Ask your doctor for labs, even if you feel healthy.
• BMI ≥27.5: Strongly consider annual labs, regardless of symptoms.

3. Look Beyond BMI

Ask about waist circumference, body fat percentage, and visceral adiposity. Tools like DEXA scans or smart scales (while not perfect) can give better context than BMI alone.

4. Lifestyle First, But Don’t Dismiss Medications

Lifestyle changes—nutrition, movement, sleep, stress management—are always the foundation. But in high-risk Asian patients, early use of medications may prevent progression.

• Metformin: Often considered in prediabetes for high-risk patients.
• GLP-1 receptor agonists (e.g., semaglutide): These medications improve insulin sensitivity and reduce progression to diabetes. They’re generally considered when:
  • Prediabetes or diabetes is already diagnosed
  • Lifestyle alone hasn’t been enough
  • BMI ≥27.5 with comorbidities, or ≥23 with strong metabolic risk factors

Always talk to a physician to weigh benefits and risks for your specific case.

The Bigger Picture

Prediabetes in Asian women isn’t a fluke—it’s a predictable outcome of how our bodies carry fat and process insulin. Standard BMI cutoffs underestimate our risk, meaning many of us slip through the cracks until we already have prediabetes.

If you’re Asian, “skinny” doesn’t guarantee protection. And if you’re a physician, it’s time to adjust your mental model of what diabetes risk “looks like.”

So the next time you’re on a girls’ trip and someone says, “But I’m skinny, how can I have prediabetes?”—you’ll know the answer. And more importantly, you’ll know what to do about it.

References

1. Mehta LS, Velarde GP, Lewey J, et al. Cardiovascular Disease Risk Factors in Women: The Impact of Race and Ethnicity: A Scientific Statement From the American Heart Association. Circulation. 2023;147(19):1471-1487. doi:10.1161/CIR.0000000000001139.
2. Misra A. Ethnic-Specific Criteria for Classification of Body Mass Index: A Perspective for Asian Indians and American Diabetes Association Position Statement. Diabetes Technol Ther. 2015;17(9):667-71. doi:10.1089/dia.2015.0007.
3. Kwan TW, Wong SS, Hong Y, et al. Epidemiology of Diabetes and Atherosclerotic Cardiovascular Disease Among Asian American Adults: Implications, Management, and Future Directions: A Scientific Statement From the American Heart Association. Circulation. 2023;148(1):74-94. doi:10.1161/CIR.0000000000001145.
4. Volgman AS, Palaniappan LS, Aggarwal NT, et al. Atherosclerotic Cardiovascular Disease in South Asians in the United States: Epidemiology, Risk Factors, and Treatments: A Scientific Statement From the American Heart Association. Circulation. 2018;138(1):e1-e34. doi:10.1161/CIR.0000000000000580.
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7. Abate N, Chandalia M. Risk of Obesity-Related Cardiometabolic Complications in Special Populations: A Crisis in Asians. Gastroenterology. 2017;152(7):1647-1655. doi:10.1053/j.gastro.2017.01.046.
8. Vicks WS, Lo JC, Guo L, et al. Prevalence of Prediabetes and Diabetes Vary by Ethnicity Among U.S. Asian Adults at Healthy Weight, Overweight, and Obesity Ranges: An Electronic Health Record Study. BMC Public Health. 2022;22(1):1954. doi:10.1186/s12889-022-14362-8.
9. Jih J, Mukherjea A, Vittinghoff E, et al. Using Appropriate Body Mass Index Cut Points for Overweight and Obesity Among Asian Americans. Prev Med. 2014;65:1-6. doi:10.1016/j.ypmed.2014.04.010.
10. Davidson KW, Barry MJ, Mangione CM, et al. Screening for Prediabetes and Type 2 Diabetes: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;326(8):736-743. doi:10.1001/jama.2021.12531.