Inadequate Hydration, BMI, and Obesity Among US Adults: NHANES 2009-2012

Abstract

PURPOSE Improving hydration is a strategy commonly used by clinicians to prevent overeating with the goal of promoting a healthy weight among patients. The relationship between weight status and hydration, however, is unclear. Our objective was to assess the relationship between inadequate hydration and BMI and inadequate hydration and obesity among adults in the United States.METHODS Our study used a nationally representative sample from the National Health and Nutrition Examination Survey (NHANES) 2009 to 2012, and included adults aged 18 to 64 years. The primary outcome of interest was body mass index (BMI), measured in continuous values and also categorized as obese (BMI ≥30) or not (BMI <30). Individuals with urine osmolality values of 800 mOsm/ kg or greater were considered to be inadequately hydrated. Linear and logistic regressions were performed with continuous BMI and obesity status as the outcomes, respectively. Models were adjusted for known confounders including age, race/ethnicity, sex, and income-to-poverty ratio. RESULTSIn this nationally representative sample (n = 9,528; weighted n = 193.7 million), 50.8% were women, 64.5% were non-Hispanic white, and the mean age was 41 years. Mean urine osmolality was 631.4 mOsm/kg (SD = 236.2 mOsm/kg); 32.6% of the sample was inadequately hydrated. In adjusted models, adults who were inadequately hydrated had higher BMIs (1.32 kg/m 2 ; 95% CI, 0.85-1.79; P <.001) and higher odds of being obese (OR = 1.59; 95% CI, 1.35-1.88; P <.001) compared with hydrated adults. CONCLUSIONWe found a significant association between inadequate hydration and elevated BMI and inadequate hydration and obesity, even after controlling for confounders. This relationship has not previously been shown on a population level and suggests that water, an essential nutrient, may deserve greater focus in weight management research and clinical strategies. 2016;14:320-324. doi: 10.1370/afm.1951. Ann Fam Med INTRODUCTIONO besity continues to be a prevalent, debilitating, and costly chronic disease in most high-income countries.1 The drivers of obesity are multifactorial and represent a major clinical challenge in both prevention and management. 2,3 In addition to replacing sugar-sweetened beverages with water, improving overall hydration is a strategy commonly used to prevent overeating, with the goal of promoting a healthy weight among patients. [4][5][6] For example, counseling patients to first drink water when they have the urge to eat, as they may actually be thirsty rather than hungry, is a recommendation clinicians give patients and is advice readily found in lay media.Water intake as a weight loss tool, however, is not an evidence-based recommendation. Recent studies have shown mixed results, likely because of limitations in the measurement of hunger and thirst, as well as the numerous social, cognitive, sensory, and logistical factors that influence eating and drinking behaviors.5 Some studies suggest that water intake may be a promising target for obesity prevention and trea...

Sustained Obesity and Depressive Symptoms over 6 Years: Race by Gender Differences in the Health and Retirement Study

“…Although, research has consistently shown that obesity impacts psychological well-being (Wynne et al, 2014; Chang et al, 2016; Global BMIMC, 2016), a growing body of evidence suggests that psychosocial correlates of obesity may depend on race (Kodjebacheva et al, 2015; Murphy et al, 2015; Kelley et al, 2016), gender (Assari and Caldwell, 2015; Kodjebacheva et al, 2015), and their intersection (Assari and Lankarani, 2015a). Whether race by gender groups differ in the link between sustained obesity and psychosocial distress is still unknown.…”

Weight management during pregnancy: a qualitative thematic analysis on knowledge, perceptions and experiences of overweight and obese women in Singapore

“…A recent finding by Chang et al [38] showed that the water ought to be better studied in the research of weight management and clinical strategies. An essential nutrient in population’s diet, potable water is usually an inexpensive commodity that is often widely available and accessible by people.…”

Shifting Focus: From Hydration for Performance to Hydration for Health

“…A commonly referenced cut-off for the upper limit of euhydration is a U Osm of 800 mOsm·kg -1 , which has been used in studies of hydration in both children [60][61][62][63] and adults [64,65] . The principle behind the 800 mOsm·kg -1 cut-off has roots in early work by Katz et al [66] , who studied the urine-concentrating capacity of the kidney in hot conditions, and determined that nearly all participants could concentrate their urine up to at least 800 mOsm·kg -1 .…”