Growth Indices of Exclusively Breastfed Until 6 Months Age and Formula‑Fed Infants in Southwest of Iran

Abstract

Background: Formula milk is prepared as a nutritional substitution for human breast milk, but
because of biologic and constituent differences, it might cause obesity and growth disorders in
infants. In this study, we compared the growth pattern of formula‑fed and breastfed infants living in
Yasuj, southwest of Iran.

Methods: Infants 7–14 months of age in southwest of Iran were classified
as exclusively breastfed (n = 200) and formula‑fed (n = 200) in their first 6 months of life. Growth
velocity and Z‑scores of weight for age, length for age, weight for length, and head circumference
were estimated using WHO Anthro Plus software (2010) and SPSS Version 19 (SPSS Inc., Chicago,
IL, USA) using World Health Organization reference for growth data.

Results: The study showed
that Z‑score of length for age and head circumference for age at the birth were significantly lower in
formula‑fed group than exclusively breastfed group (P < 0.05), but the Z‑score of weight for length
did not differ significantly. At the sixth month of age, Z‑score of weight for length was significantly
higher in formula‑fed group (P < 0.05), but Z‑score of length for age had no significant difference
and Z‑score of head circumference was higher in exclusively breastfed group yet (P < 0.05). Growth
velocity, prevalence of obesity, wasting, underweight, and stunting did not differ between two groups.
Conclusions: Our findings suggest that formula feeding can lead to greater weight gain and may
help the catch up of length, but evidences are not convincing enough to suggest the formula as an
obesogenic feeding in the studied area. To make a conclusion, we suggest comparing the privileged
and unprivileged areas and controlling for confounding variables including family hygiene and infant
feeding practices between formula‑fed and breastfed infants.
Keywords: Breastfeeding, formula feeding, growth velocity