Date of Award

Summer 6-17-2017

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Nutrition

First Advisor

Desiree Wanders

Second Advisor

Michelle Lampl

Third Advisor

Sarah Henes

Abstract

Background: Fat distribution, rather than total body fat, has been identified as a significant risk factor for chronic disease. Patterning of subcutaneous fat, in particular, may play a pervasive role in shaping the metabolic milieu that is critical for disease development. Several studies have shown that early-life nutrition may influence later body composition. The effect of breastfeeding and formula feeding on early patterns of subcutaneous fat deposition, however, are uncertain.

Objective: At a time when early infant growth is emerging as a predictor for later chronic disease, it is the aim of the present analysis to investigate whether feeding style (breastfeeding versus formula feeding) modifies subcutaneous fat growth rates and trajectories in the first year of life with a focus on the historical iterations of WHO infant feeding recommendations (0 to 4 months, 4 to 6 months, and 6 to 12 months of age).

Methods: This is an ex post-facto design that utilizes data collected as part of a longitudinal growth study in the first year of life. Subcutaneous fat mass was anthropometrically assessed weekly by skinfold thickness (triceps, quadriceps, calf, subscapular, suprailiac, midaxillary, and abdominal) in 21 infants. Feeding data were collected through daily parental records and are entered here as a categorical variable (predominantly breast fed and predominantly formula fed). Multi-level mixed effects models for repeated measures were used (STATA 14) adjusting for age, sex, weight, birthweight, and number of feeding episodes per day. Statistical significance was accepted at p

Results:Infants experienced fat accretion only during the first four months, and this was limited to peripheral skinfolds. Thereafter, subcutaneous skinfolds followed a trend of declining rates. Breastfed and formula fed infants, however, demonstrated different patterns of subcutaneous fat deposition in both the sum of skinfolds and in each skinfold site. During the first four months, formula fed infants experienced greater rates for the subscapular, abdominal, suprailiac, trunk, quadriceps, sum of skinfolds (p

Conclusion: Weekly skinfold assessments of seven subcutaneous sites have identified that feeding style predicts differences in deposition patterns in the first year of life. Breastfed infants demonstrated both slower rates of accretion and decline by comparison with their formula fed peers. This analysis further suggests that the first four months may be a critical period for subcutaneous fat deposition. Feeding specific effects were identified for truncal deposition and utilization, which suggests that future studies may benefit from depot-specific inquiries.

Available for download on Friday, July 12, 2019

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