Breastfeeding significantly reduces weight and insulin levels at 6-8 weeks after delivery regardless of diabetes

An analysis conducted at 6-8 weeks after delivery revealed that breastfeeding contributed to lower insulin levels, and at one year postpartum, it resulted in lower thickness of subcutaneous (SC) fat tissue suggesting that a greater fat metabolism is obtained in breastfeeding rather than in non-breastfeeding women. The study findings were published online in the journal Nutrients. 

The results of the anthropometric measurements and hormone levels noted at 6–8 weeks after delivery were not affected by having diabetes during pregnancy; the only exception was the thickness of SC fat tissue, which was higher in women without GDM. This implies normalization of carbohydrate metabolism after childbirth, however, the researchers noted observation period is too short to elucidate long-term metabolic effects, especially considering that one year after giving birth, women without GDM showed slightly better results in anthropometric measurements than those without GDM.

Breastfeeding may have a positive impact on insulin sensitivity and glucose metabolism, which may reduce the risk of diabetes development following GDM. Dorota C´wiek, Pomeranian Medical University in Szczecin, Szczecin, Poland, and colleagues aimed to evaluate the effect of breastfeeding and gestational diabetes on the body mass composition of the studied women, the levels of ghrelin, leptin, resistin, adiponectin, and insulin, and weight loss during the 6-8-week postpartum period and one year after childbirth.

The study group included 42 women with a singleton pregnancy, diagnosed with gestational diabetes between the 24th and 28th week of gestation. The control group comprised 28 non-diabetic women with a singleton pregnancy.

The study was conducted at 6-8 weeks and 1 year postpartum. The women were subjected to body composition analysis and body weight measurements performed using a professional body composition analyzer TANITA DC-430 S MA. Waist circumference and SC fat were measured. Blood for laboratory tests was taken on an empty stomach in the morning.

Based on the study, the researchers reported the following findings:

• Regardless of diabetes, exclusive breastfeeding had a significant impact on weight loss at 6-8 weeks postpartum and lower insulin levels.
• There was no effect of breastfeeding on the women's anthropometric measurements or hormone levels one year after delivery, except for the thickness of SC adipose tissue, which was significantly lower in breastfeeding women.
• One year after delivery, breastfeeding women had a lower BMI, less thick subcutaneous adipose tissue, and a lower risk of obesity.
• There were also higher insulin and ghrelin levels in both breastfeeding and non-breastfeeding women and lower resistin levels in non-breastfeeding women.
• Women who had diabetes during pregnancy had a significantly reduced waist circumference and subcutaneous fat thickness after one year.

The researchers suggest the need for further research related to gestational diabetes and breastfeeding.

The limitation of the study is the homogeneity of the research sample; the study included only women of similar ethnic origin. Also, there is a lack of data regarding glycemic control (i.e. HbA1c or glucose levels) in the one year after delivery. Also, there is a need to better understand the mechanisms of how lactation affects GDM, BMI, and body weight composition.

Reference:

Ćwiek, Dorota, et al. "The Effects of Breastfeeding and Gestational Diabetes Mellitus On Body Mass Composition and the Levels of Selected Hormones After Childbirth." Nutrients, vol. 15, no. 22, 2023.