The impact of living in a ‘food desert’ on metabolic health during pregnancy

Metabolic health during pregnancy is essential for both the mother and child; however, several factors, including socioeconomic status (SES) and access to healthy food, can disrupt a woman’s metabolic health during pregnancy. A new paper in Scientific Reports explores the roles of these factors during pregnancy.

Study: The association between food desert severity, socioeconomic status, and metabolic state during pregnancy in a prospective longitudinal cohort. Image Credit: Kwangmoozaa / Shutterstock.com

Introduction

Metabolic dysregulation during pregnancy is associated with several maternal and fetal complications. Fetal problems may include preterm birth, stillbirth, neonatal death, heavy babies, low birth weight, and macrosomia, as well as obesity, metabolic disorders, and an increased risk of aberrant neurodevelopment later in life.

For the mother, metabolic dysregulation during pregnancy may predispose them to long-term medical complications, such as cardiometabolic disorders, renal disease, and urological disease.

The health effects of living in a ‘food desert’

To promote a healthy metabolism during pregnancy, the woman should be able to access and afford healthy food. A ‘food desert’ refers to an area of low-income families with little access to healthy foods.

People living in food deserts are at an increased risk of poor-quality diets, obesity, and nutrient deficiencies, as well as having a low SES. A lower SES increases a pregnant woman’s risk of metabolic complications, including gestational diabetes mellitus (GDM), excessive weight gain, obesity, and metabolic syndrome.

Living in a food desert increases the risk of medical and metabolic complications during pregnancy. For example, one earlier study reported an increased risk of GDM in women living in neighborhoods with fewer grocery stores.

This may be due to both living in a food desert as well as increased consumption of pro-inflammatory food, both of which are associated with poor metabolic health in non-pregnant people. This population is also more likely to receive suboptimal prenatal care and experience chronic stress.

About the study

Researchers also sought to explore if both a low SES and living in a food desert are independent risk factors for poor metabolic balance in pregnancy.  

The current study included 302 pregnant women whose SES was determined based on total household income for size, education, and reserve savings. The participants’ level of access to healthy and affordable foods, or food desert severity, was determined according to the United States Department of Agriculture Food Access Research Atlas.

Participants underwent an oral glucose tolerance test (OGTT) in the second trimester. The first-hour glucose levels were used for the study, along with percent adiposity by air displacement plethysmography.

Accurate nutritional information was approximated by three 24-hour dietary recall visits made by trained nutritionists without notice to the homes of the participants.

What did the study show?

Pregnant patients with a lower SES were more likely to live in a severe food desert. During the second trimester, these women were also more likely to have worse metabolic health, which included higher percent adiposity, as well as consume a more pro-inflammatory diet. However, women with a low SES were not at an increased risk of higher blood sugar levels.

Interactions between these factors were also observed, with greater food desert severity being a predictor of higher percent adiposity but not higher glucose concentrations in the second trimester. The association between lower SES and adiposity was due to the lack of access to affordable and healthy foods.

Older mothers were less likely to have a lower SES, while mothers using alcohol were more likely to live in a food desert. Those who used prenatal vitamins were more likely to have higher adiposity and SES.

Mothers from ethnic minorities were more likely to have higher glucose levels. Pregnant women with higher blood glucose levels were more likely to have a greater fat mass. Similarly, pregnant women with increased fat mass were more likely to have high blood glucose concentrations and consume more inflammatory foods.

What are the implications?

Both SES and food desert severity were found to affect metabolic health in pregnancy. These findings corroborate earlier research showing that people with a lower SES are more likely to have excessive fat mass, live in a severe food desert, and consume inflammatory foods.

The glucose concentration in pregnancy was also associated with an inflammatory diet. The importance of living in a food desert has previously been linked to obesity and is independent of, though related to, the impact of SES.

Further research is needed to measure the contribution of food desert severity more accurately using characteristics other than geographical location. Notably, geographic location does not account for financial and other differences that may compensate for the difficulty in accessing healthy food in these places.

Thus, those with the resources to buy healthy food may not suffer from the metabolic effects of living in a food desert.

The impact of SES on fat mass during pregnancy is related to food desert severity; however, both SES and fat mass effects are independent of the effect of inflammatory food consumption. Earlier studies have shown the contrary, where food desert residence is linked to poor fruit and vegetable consumption, both of which are proxies for an unhealthy diet. Other possible mechanisms in which food desert severity leads to increased adiposity in pregnancy may include increased stress due to low SES.

These findings indicate that access to healthful and affordable foods is a mechanism by which SES contributes to adiposity during pregnancy and may inform interventions intended to improve metabolic health during pregnancy.”

Moreover, understanding the mechanisms of weight gain, specifically fat mass increase, in pregnancy may help identify high-risk individuals. This data could also facilitate the implementation of appropriate interventions, such as encouraging physical activity, training in healthy cooking and eating, promoting community gardens, and supplementary nutrition or meal programs.

At the policy level, low-income communities should be prioritized for increasing the availability of grocery stores to provide a source of healthy food while regulating food quality at convenience food outlets.