Maternal Body Mass Index and Presence of Appetite Regulating Hormones and Other Factors in Human Breast Milk
Authors: Clark William Andrew , Kwon Megan Ripperger , Cress Eileen M. , Hamdy Ronald C. , Cobarrubias Heidi , Luttrell Sarah , Stone William L. , Brannon Marianne , Peterson Jonathan M. 
Published: November 2023

Exposure to over nutrition in critical development periods (neonatal nutrition) may increase the risk of obesity or developing metabolic syndrome in adulthood. Human breast milk (~ 125 ml, BRM), between 2 and 14 weeks of lactation, was collected from 45 Caucasian women (24 normal weight (NW, BMI 18.5 to 24.9 kg/m2) and 21 overweight/obese (OW, BMI >25.0 kg/m2)). A 10 ml aliquot was frozen (−80°C) for analysis of appetite regulating hormones and other factors and the remaining volume was freeze dried and subjected to proximate analysis. Participants also completed food frequency questionnaires (FFQ) to estimate fruit, vegetable, and fat intake. Insulin (182.3 vs 537.1 pg/ml, p=0.0001), leptin (186.8 vs 911.3 pg/ml, p=0.0001) were lower, and alpha‐tocopherol (7.39 vs 5.03 uM/ml, p=0.009) higher in NW vs OW BRM. When the data set was reconfigured to compare BRM from lactating women with pre‐gravid BMI ≤ 24 (n=19) or ≥30 (n=15), insulin (200.6 vs 534.8 pg/ml, p=0.003) and leptin (200.3 vs 1,030.9 pg/ml, p=0.0001) were lower and adiponectin (12,349.8 vs 8,696.8 pg/ml, p=0.052) and alpha‐tocopherol (7.72 vs 4.48 uM/ml, p=0.001) were higher for normal weight versus obese women. No statistical difference was observed for levels of ghrelin, IL‐6, TNF‐α or γ –or Δ‐tocopherol in the BRM for the two groups of women. Analysis of Fruit and Vegetable FFQ revealed no significant differences in fruit and vegetable servings/day or intake of vitamin C, magnesium, potassium and dietary fiber. No significant differences were noted between NW and OW groups for total dietary fat (%), intake of fat (g), or intake of saturated fat, unsaturated fat, or total cholesterol. Pre‐gravid BMI (22.0 vs 33.7, p=0.0001), BMI at age 18 (20.4 vs 27.8, p=0.0001), and highest BMI (23.4 vs 35.6, p=0.0001), all self‐reported, are shown for the NW and OW groups. Macronutrient composition of freeze‐dried BRM were similar for total calories (5,600 vs 5,588 cal/g DM, p=0.935), protein (9.3 vs 8.2 % DM, p=0.171, fat (43.8 vs 44.4 %, p=.687) and inorganic content (1.39 vs 1.54 % DM, p=0.434) for NW and OW groups. Gas chromatography (GC) of fatty acid methyl esters, generated from freeze dried BRM, demonstrated NW BRM contained higher levels of n‐3 fatty acids, MUFA, and less palmitic acid. The increased palmitic acid level seen in OW BRM may support increased de novo synthesis of fatty acids. Understanding the nutrient, hormone, adipokine, and inflammatory compound composition of BRM from women of differing BMI's may help to optimize neonate nutrition.

Support or Funding Information

Supported by ETSU Honor's College Student‐Faculty Collaborative Research Grant and a Small Research Development Committee Grant from ETSU's Office of Sponsored Programs and Research. Appreciation to Medela Inc. Breastfeeding USA, McHenry, IL for supplying a breast pump for research participants.