Corn Syrup Solids in Formula and Risk of Childhood Obesity

CQ #262 - November 7, 2022

by Anne Eglash MD, IBCLC, FABM

#LactFact

Formula with corn syrup solids increases the risk of childhood obesity beyond that associated with non-corn syrup solids formula.

Lactose-reduced infant formula with corn syrup solids and obesity risk among participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)
Am J Clin Nutr 2022; 116: 1002-1009

Does formula with corn syrup solids increase the risk of childhood obesity compared to formula with lactose?

It is irrefutable that formula fed infants have a substantially increased risk of childhood obesity as compared to breastfed infants, and these children carry an increased risk of obesity in adulthood.

There has been discussion for many years about the use of corn syrup solids (CSS) as the main absorbable carbohydrate in infant formula because it has a higher glycemic index than lactose. CSS are not the same as high fructose corn syrup.

The glycemic index (GI) of a food is a measure of how high the blood sugar will rise after consumption. Foods are given a score of 1-100, and the higher the score, the higher and faster the rise of blood sugar. For example, the GI of an apple is 36 +/-2, the GI of grapes is 53, while the GI of black beans is 30. Foods with a higher GI cause a rapid increase in blood sugar, triggering release of insulin, followed by a drop in blood sugar (sugar crash), resulting in hunger and the risk of overeating. Because lower GI foods lead to a slower release of sugar into the blood stream, insulin remains lower, with less chance of overeating.

Because CSS have a GI of 100, compared to 46 for lactose (the natural sugar in breastmilk), there is concern that CSS formula vs formula with lactose further increases the risk of childhood obesity beyond what we see as a baseline risk for formula fed infants.

The authors of the study for this week followed weights of children who received CSS formula vs other types of formula thru the US Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). The data was collected from a large WIC agency in Southern California from September 2012 to March 2016 and included infants who stopped breastfeeding by 3 months and received formula for the rest of their first year. Data on BMIs between ages 24 and 60 months were evaluated based on formula type.

Most children in the study (87.5%) were Hispanic, 79.6% had an income below 100% of the federal poverty level, and the children were breastfed for 1 month on average. The children who received formula with CSS had a lower weight-for-age and weight-for-length measurements at baseline, at 3-5 months of age.

What was the impact of CSS formula on the risk of obesity? See the question!

What do you think are accurate statements regarding the relationship between childhood obesity and the intake of CSS formula, as compared to formula sweetened with lactose or other sugars? Choose 1 or more:

The infants with a high BMI at 3 months (baseline) were at risk for obesity if they received CSS formula, not the infants with a normal or low BMI at 3 months of age.
The children with any issuance of CSS formula had a 10% absolute increased risk of obesity at age 2 compared to children who were never given CSS formula.
Each additional month of CSS formula further increased the risk of obesity.
By 4 years of age, there was no longer a higher risk of obesity among the children who were fed CSS formula in the first year.

Click here to view the answer to this question.

Correct Answers: B and C (not A or D)

Abstract

Background

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), a federal nutrition assistance program supporting low-income families, serves half of United States–born infants, most of whom are issued infant formula by age 2 mo. Obesity prevalence is high among children of low-income households, particularly formula-fed children.

Objectives

This study was conducted to determine whether glucose based lactose-reduced infant formula made with corn syrup solids (CSSF) is associated with increased obesity risk compared with non- CSSFs that are lactose based.

Design

WIC administrative data on infant formula issuance and child weights and lengths were collected prospectively in Southern California between 2012 and 2020. Included children stopped breastfeeding by 3 mo, were issued cow’s milk–based formula through 12 mo, and were enrolled through the final year of WIC eligibility at age 4 y (n = 15,246). CSSF issuance was assessed continuously (range 0–13 mo) and dichotomously (any, none). Poisson and linear risk regression with robust SE estimates generated risk ratios (RRs), risk differences, and CIs for child obesity [BMI for age (in kg/m 2) ≥95th percentile].

Results

Any CSSF was issued to 23% of children, and 25% were obese at age 4 y. Children with any CSSF issuance had 10% higher obesity risk (RR: 1.10; 95% CI: 1.02, 1.20) than children with no CSSF issuance at age 2 y. Associations remained significant through age 4 y (RR: 1.07; 95% CI: 1.01,1.14), independent of maternal weight status, total formula issued and breastfeeding duration, and were not modified by child race or sex. Obesity risk increased with additional mo of CSSF exposure, reaching 16% higher risk (RR: 1.16; 95% CI: 1.05, 1.28) at age 2 y for children with 12 mo of CSSF.

Conclusions

CSSF issuance is associated with increased obesity risk in the first 5 y life in a dose dependent manner, independently of maternal weight status, breastfeeding duration, and total formula issuance.

IABLE Comment by Anne Eglash MD, IBCLC, FABM

The BMI at 3 months of age did not alter the risk of obesity associated with CSS formula intake at ages 2 and 4. The children who were fed CSS formula in the first year had higher BMIs at age 4 in addition to age 2. More months of CSS formula intake raised the risk of childhood obesity at ages 2 and 4.

It seems clear from this well-designed study that CSS formulas should not be recommended to formula fed infants. Lactose, as a sweetener, is ideal as it has a lower glycemic index, and is the natural sugar in breastmilk.

Non-lactose containing formulas are often recommended to families based on a belief that infant fussiness may be due to lactose intolerance. Because lactose is the natural sugar in breastmilk, it is highly unlikely that infants would be intolerance to lactose.

Check out this interview with one of the researchers, Dr. Goran. When asked why corn syrup solids are used in infant formula, he surmised that it is less expensive, thus allowing for higher corporate profits. Enfamil tells families that CSS are safe.

According to the Washington Post in May 2022, European standards for infant formula are updated regularly, whereas the US has not made a major update to their infant formula standards since the Infant Formula Act of 1980 (before the glycemic index concept in 1981). Therefore, European regulations differ, such as requiring DHA and not allowing CSS.

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Comments (3)

Beth

November 13, 2022 at 12:38 PM

This is fascinating!! So many of my patients ask about formulas from Europe and I’ve wondered how to counsel them. Of course those with WIC don’t have thie option . Are the U.S. formulas that don’t contain CSS inferior in other ways to European formulas? DHA content or source? Thank you for this!

Tara Williams

December 3, 2022 at 9:12 AM

Important study. Hopefully the recent formula crisis and studies like these will help shed some light into the dark world of unethical formula marketing.

Amy Kaplan

January 10, 2023 at 3:08 PM

Really interesting article! The thing that’s so tricky though is that the formulas that have the reduced lactose also are also the ones that have partially hydrolyzed proteins, which can be beneficial with cow’s milk protein intolerance. It seems like it’s such a trade off!