Obesity, Diabetes in Women Linked to Their Birth Weight

Marlene Busko

February 23, 2022

The study covered in this summary was published in ResearchSquare as a preprint and has not yet been peer reviewed.

Key Takeaways

  • In a study of just over 4000 middle-aged women in China, researchers found:

    • A U-shaped relationship between low, normal, or high birth weight and risk of adult obesity, with the lowest risk at a birth weight of 3000 g (the midpoint of the normal birth weight range of 2500 g to < 3500 g).

    • Risk of type 2 diabetes in normal-weight women was highest in those with a low birth weight and decreased as birth weight increased.

  • Among these middle-aged women, those with a high birth weight had a high obesity rate but a low prevalence of type 2 diabetes, whereas those with a low birth weight had a high obesity rate and a high prevalence of type 2 diabetes.

  • Women with overweight or obesity had a higher prevalence of type 2 diabetes, independent of their birth weight.

  • Women with a lower birth weight and overweight or obesity had the highest prevalence of type 2 diabetes.

Why This Matters

  • The results confirmed that overall low birth weight is associated with increased risk of having type 2 diabetes in middle-aged women.

  • The results also showed that overweight or obesity in middle age upped the risk of diabetes, independent of birth weight.

Study Design

  • Researchers used social media, including TikTok and WeChat, to randomly invite women in China who watched certain health videos to participate in the study and answer an 18-item online questionnaire from December 2020 to June 2021.

  • The 4005 women from 10 provinces in China who participated all knew whether they had type 2 diabetes, had no history of gestational diabetes, or severe liver or kidney disease, and were able to use the study software for data collection.

Key Results

  • The women averaged 49 years old, had a mean birth weight of 3063 g, and had a mean body mass index (BMI) of 23.4 kg/m2.

  • 14.8% had hypertension, 3.7% had type 2 diabetes, and 7.3% had obesity (BMI > 28 kg/m2).

  • Researchers divided the women into three groups, based on birth weight:

    • Low birth weight, < 2500 g (5.5 pounds): 18.6%

    • Normal birth weight, 2500-3500 g (5.5-7.7 pounds): 68.7%

    • High birth weight, > 3500 g (> 7.7 pounds): 12.7%

  • Women in the three birth-weight groups had the following prevalence of diabetes and obesity:

    • Low birth weight: 5.2% had type 2 diabetes and 8.1% had obesity.

    • Normal birth weight: 3.6% had type 2 diabetes and 6.7% had obesity.

    • High birth weight: 2.0% had type 2 diabetes and 9.0% had obesity.

  • As birth weight increased, the prevalence of type 2 diabetes significantly decreased. After adjusting for age, BMI, and hypertension status, the normal birth weight group was not significantly different from the lower birth weight group, but the higher birth weight group remained significantly below the lower birth weight group for prevalence of type 2 diabetes.

  • A deeper dive showed that women with overweight or obesity did not have a lower prevalence of type 2 diabetes with increasing birth weight, but this relationship was significant among women with normal body weight.


  • Most study variables were self-reported given the study's reliance on Internet-based reporting, an approach that may have produced reporting errors.

  • The study likely underestimated the true prevalence of type 2 diabetes. Roughly half the people with diabetes in China have not received a diagnosis.


  • The study did not receive commercial funding.

  • The authors report no relevant financial disclosures.

This is a summary of a preprint research study, "Birth weight is associated with obesity and T2DM in adulthood among Chinese women," written by researchers from Xuzhou Central Hospital and Xuzhou Medical University, in Xuzhou, China. Preprints from ResearchSquare are provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on researchsquare.com.


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