New study explores origin of obesity

New study explores origin of obesity

January 9, 2018

  • Elizabeth Reifsnider is a researcher in the Biodesign Center for Fundamental and Applied Microbiomics. She is Associate Dean for Research and Professor, College of Nursing and Health Innovation


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January 9, 2018

More than almost any other medical hazard, obesity holds widespread consequences for human health. The condition sharply raises the risk of diabetes, high blood pressure, coronary artery disease, stroke, cancer, gall bladder dysfunction, osteoarthritis, metabolic syndrome… and the list goes on.

Recent research highlights the fact that obesity can have its roots in infancy and early childhood, with the results persisting into adulthood, underscoring the need for aggressive intervention at the earliest stage. The problem is particularly acute in high-risk populations, including low-income immigrant communities.

In a new study, Elizabeth Reifsnider, a researcher at the Biodesign Center for Fundamental and Applied Microbiomics, along with her colleagues at the University of Texas and Baylor College of Medicine, report on a new clinical trial aimed at stemming the tide of overweight infants.   

To accomplish this, the study applied an educational program to be delivered during pregnancy, designed for obese Latina women living in a southwestern metropolitan area. The expectant mothers were all of Hispanic origin, earned below 185 percent of the federal poverty index and were enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).  These and related socioeconomic issues make these women vulnerable to delivering overweight infants, who run an elevated risk of future obesity-related illness.

“Our study showed that obesity can develop early and easily in infants, but breastfeeding can be protective,” Reifsnider said.  “Our next step in the research will be to examine how breast milk encourages the growth of the infants’ microbiomes to promote healthy growth and avoid infant overweight/obesity.”

The research findings appear in the current issue of the journal Academic Pediatrics.

The first-of-its-kind educational program was carried out in the homes of the study subjects in an effort to reduce the incidence of overweight infants measured at 12 months. The participants in the program were healthy Latina women in the third trimester of pregnancy, ages 18-40 years, with a pre-pregnancy BMI ≥ 25. (A BMI equal to or greater than 25 is considered overweight and above 30 is considered obese.) All subjects were reachable by phone, able to receive visitors at home, and did not intend to move from the area.

Excluded were mothers with high-risk pregnancies, postpartum complications and/or hospitalization or separation from their infant.

The program was conducted in collaboration with the City of Houston Department of Health’s Supplemental Nutrition Program for Women, Infants, and Children (WIC), an initiative funded by the United States Department of Agriculture, which provides nutrition education and breastfeeding support services, supplemental nutritious foods and referrals to health and social services. WIC provides nutrition education and vouchers for healthy food for pregnant, breastfeeding, and postpartum women; infants; and children under the age of five who are at or below 185% of Federal Poverty level and determined to be at nutritional risk.

Studies have shown that WIC participation reduces the incidence of low birth weight, improves the nutrient intake, prevents iron deficiency, improves immunization rates, and improves childhood access to regular medical care.

Pregnant obese women were recruited into the program through WIC and were randomly assigned to one of two groups: controls (who did not receive the intervention) and intervention subjects who received home visits during their children’s first three years of live to prevent development of obesity in their children.

Those selected for intervention received home visits by trained, Spanish-fluent community health workers, known as promotoras, who received six months of formal instruction and had community health worker certification. Promotoras play a traditional role in Hispanic culture as trusted individuals able to disseminate health information through interpersonal networks.

Promotoras provided expectant mothers with 9 home visits across 3 years, usually lasting one hour of in-home counseling on topics including infant and child growth, breastfeeding, nutrition, child development, sleep, physical activity, safety and sleep hygiene.

Unfortunately, the program of parent education did not reduce levels of overweight infants observed. Typically, the condition developed rapidly following birth in 46 percent of infants and was increasingly apparent by six months of age. Further, infants who were measured as overweight at six months of age were more likely to test overweight at 12 months.

The study observed a number of intriguing trends, however. Infants were more likely to be overweight at six months and 12 months if they were formula fed. Families where the mother was employed and the father unemployed showed lower rates of breastfeeding.

In analyzing the lack of success of the intervention program, the authors note the high rate of caesarean section among mothers in the study as well as food and employment insecurity. Results showed that breastfeeding was the most important single factor reducing the likelihood of overweight infants, reinforcing the recommendations of WIC to strenuously promote breastfeeding. Breastfed infants were 2.7 times less likely to be overweight at age 12 months, compared with formula-fed infants.

A variety of stress factors are believed to influence infant outcomes relating to weight. Some of these include lack of family support, divorce or separation, lack of financial support from the father, spousal abuse, father’s unemployment, inability to speak English, illiteracy in English and/or Spanish, household crowding, inability to take time off from work or school to care for the baby, lack of transportation, lack of medical/psychological care for self and/or family members, anxiety and depression.

Mothers who breastfed for two months were more likely to have been living with fathers at the time of their prenatal visit to WIC, suggesting that emotional and financial support from the father plays an important role and appears to improve weight outcomes for infants 12 months of age, likely due to increased rates of breastfeeding.

The study reaffirms WIC’s emphasis on vigorously promoting breastfeeding as an identifiable method of reducing the rate of overweight infants and children. Success in this important area would be certain to pay rich dividends in public health over time, as adult obesity-related illnesses are reduced through early intervention.

 

Funded by the National Institutes of Health. 5R01DK096488

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Written by: richard harth