The Need for Targeted Weight-Control Approaches in Young Women and Men

In this issue of the American Journal of Preventive Medicine, Brown et al.¹ investigate the role that pregnancy plays in 10-year weight gain among a cohort of Australian women who were initially aged 18–23 years. Their results, based on women who were mostly nulliparous and unmarried at baseline, are consistent with previous findings suggesting that childbearing is a significant predictor of later weight gain.^2–4 More than 40% of pregnant women in the U.S. gain weight in excess of recommended amounts; the IOM recently updated their guidelines for how much weight women should gain during pregnancy.⁵ Once gained, excess pregnancy weight is difficult to lose and may be associated with an increased risk of developing obesity, diabetes, and cardiovascular disease (CVD) later in life.^6,7 Given that women who enter pregnancy overweight or obese are at higher risk of adverse pregnancy outcomes, such as preeclampsia, gestational diabetes, fetal macrosomia, cesarean delivery⁸ and postpartum weight retention,⁶ it would be beneficial for women to attain a healthy weight before they consider pregnancy. However, about 50% of U.S. women of childbearing age are overweight or obese,⁹ and nearly 50% of pregnancies are unplanned.¹⁰

Few researchers have tried to disentangle the role of pregnancy from other factors. Brown et al.¹ also conclude that living with a partner but not having a child is associated with higher 10-year weight gain than not having a partner and child. In another recent study, young adults who transitioned from being single or dating to cohabitating or married were more likely to become obese over the next 5–6 years than those not making that transition.¹¹ These two findings suggest that living with a partner itself in addition to pregnancy puts young women at higher risk of obesity. The results of a research by The and Gordon-Larsen¹¹ apply also to young men, but the relationship between parenting and weight gain among men is less well studied. Early adulthood is a time of life-changing events, such as moving away from family and entering the work force, in addition to marriage and parenting. The changing social and environmental context associated with these life changes may profoundly affect weight gain for both young women and men. Indeed, young adults gain 1–2 pounds per year, with the largest weight gain—almost 3 pounds/year—occurring between the ages of 20 and 29 years.¹² Excess weight gain early in adulthood is associated with later, more adverse levels of CVD risk factors, such as hypertension, dyslipidemia, and diabetes.^13,14

Despite the high risk for weight gain early in adulthood and the subsequent increased risk of adverse outcomes, few studies have tested behavioral interventions aimed at young adults. A few studies have focused on preventing excessive weight gain during pregnancy^15–18 or returning to pre-pregnancy weight^19,20 but for the most part, these studies have been small, with high attrition and limited generalizability. A similarly small number of studies have targeted weight control among young adults in general.^21–23 Although eligible for adult weight-loss studies, young adult participants usually have less weight loss and higher attrition rates than older participants.²⁴

In general, the interventions tested to date have had varying success, suggesting that a better understanding of influences and barriers is pivotal in developing interventions that will appeal to young adults. As with older adults, influences on obesity-related behaviors—particularly dietary intake and physical activity—are multi-factorial, including physiology, family, peers, community, culture, and the environment. However, such influences may differ in their importance to young adults. For example, young adults may be more sensitive to peer pressure, have fewer economic resources, and may be less motivated to adopt healthy behaviors because they perceive health consequences to be distal. New parents may face unique barriers, such as time and energy constraints due to balancing child care, work, and home responsibilities. On the other hand, pregnant women and new parents may be more motivated to control their own weight if they realize that such changes may also benefit their children’s health.²⁵

The National Heart, Lung, and Blood Institute and the Eunice Kennedy Shriver National Institute of Child Health and Human Development recently funded six studies that may begin to fill the interventional research gap related to weight control in young adults. Recognizing that weight-control approaches will need to be targeted toward this age group, each study will conduct formative research to refine the proposed intervention, recruitment, retention, and adherence strategies. Incorporating what was learned during the formative phase, each study will conduct a 2-year RCT to test the efficacy of the behavioral interventions that address weight loss, prevention of weight gain, or prevention of excessive peripartum weight gain. Specific target populations include pregnant and postpartum women, community college or university students, and young adults trying to quit smoking. The trials will have racial/ethnic, gender, and socioeconomic diversity across the study populations.

While the interventions build on proven approaches for older adults, they are adapted to be more appealing to young adults. To do this, most plan to use technology-driven methods such as mobile phones, social networks, Internet programs, and web-based curricula. The use of technology to deliver interventions may also reduce participant burden, a critical consideration for pregnant women and new parents. These interventions have the potential to be practical, cost-effective, and easily disseminated on a broad scale if they are proven efficacious. Successful interventions can not only help young adults achieve and maintain a healthy weight, but may prevent or delay the development of many chronic diseases and other obesity-related adverse outcomes. Moreover, by improving health behaviors in adults of childbearing age, these interventions may lead to healthier behaviors and weights for the next generation of children.