A positive association between dietary sodium intake and obesity and central obesity: results from the National Health and Nutrition Examination Survey 1999-2006

Abstract

The link between sodium and obesity has been accumulated over years. However, there has been few data reported on such sodium-obesity association from the general US population. This study is designed to assess the hypothesis that dietary sodium intake is independently and positively associated with obesity, central obesity, and measures of body composition among generally healthy US adults. We analyzed data on 9162 healthy participants aged 24 to 48 years (4813 men and 4349 women) with at least one valid diet recall from the 8-year National Health and Nutrition Examination Survey (1999-2006). Measures of body composition, including fat mass, lean mass, and total fat percent, were determined by dual-energy x-ray absorptiometry. We assessed the association between dietary sodium and obesity and measures of body composition by using multivariable logistic regression models. After adjustment for total energy intake and other prespecified confounders, high sodium intake (>2300 mg/d) was significantly associated with elevated risk of obesity and central obesity as compared with moderate sodium intake (1500-2300 mg/d). On average, each 1-g/d increment in dietary sodium intake resulted in a 15% (odds ratio, 1.15; 95% confidence interval, 1.00-1.33) increase in the risk of obesity and 24% (odds ratio, 1.24; 95% confidence interval, 1.11-1.39) increase in the risk of central obesity. After stratification by sex and ethnicity, significant associations between sodium and obesity/abdominal obesity were apparent only among women and non-Hispanic whites. In addition, all measures of body composition were positively associated with sodium consumption levels. We found that high sodium intake is independently associated with elevated risk of obesity and central obesity in the general US adult population.

The association between dietary sodium intake, adiposity and sugar-sweetened beverages in children and adults: a systematic review and meta-analysis

“…Reasons for exclusion from metaanalyses included; findings were only presented as correlation coefficients (n=16) (35, 54-56, 61, 68, 77, 78, 81, 82, 84, 86, 87, 90, 92, 96) or as standardised regression coefficients (n=4) (57,64,89,94) , the exposure variable was presented as sodium density (n=2) (12,72) or 24-hr urinary sodium excretion was reported as sodium concentration (mmol/L) (74) or on a logarithmic scale (52,58) . Of the studies included in meta-analyses, 14 were from Asia (62,63,66,69,70,73,75,76,83,85,91,97,100,101) , eight from USA (10,11,59,60,71,88,102,103) , five from South and Central America (53,65,79,80,93) , four from Europe (9,67,95,99) , one from Samoa (98) and one included data collected across four countries (e.g. Japan, USA, UK, China) (104) .…”

“…Most of these studies (24/33) reported on more than one adiposity outcome (Table S3). Outcomes which were included in separate meta-analyses were BMI (n=31) (9-11, 53, 59, 60, 63, 65-67, 69-71, 73, 75, 76, 79, 80, 83, 85, 88, 93, 95, 97-104) , weight category (n=8) (9,11,63,73,91,97,103,104) , BW (n=7) (60,65,67,71,73,93,101) , WC (n=9) (9,65,66,70,73,75,80,83,100) and abdominal obesity (n=5) (62,66,73,102,103) . Only nine studies adjusted for energy intake (9,10,59,66,73,91,(102)(103)(104) and three studies adjusted for SSB intake (9,11,103) .…”

Salt need needs investigation

“…The determinants of our excessive salt appetite have been scarcely researched and, consequently, are scarcely understood (14)(15)(16)(17)(18) . Research has been primarily into the consequences of salt intake, primarily comprising large-scale studies, which have engendered the consensus that salt is toxic, along with a nuanced contention that it is less so (7,(9)(10)(11)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) .…”

“…Today, worldwide, salt is consumed daily, repeatedly, totalling an amount that is in excess of that required to preserve life, which many hold to increase society's disease burden, vascular and cancerous, significantly and cause three million deaths annually (7) . Obesity is estimated to cause four million deaths (8) , but a million of those may be due to salt intake (9)(10)(11) , so that while the two may be similarly deadly, the causes of obesity are researched incomparably more (12,13) . The reason for this is not clear, but it may be that obesity is prominently visible, whereas salt is allied to a silent killer, hypertension (13) .…”

Test of the hypothesis that eating high-salt food leads to obesity by stimulating sugar-solution consumption

“…There is strong epidemiological evidence for a positive association between salt consumption and body weight [1][2][3][4][5][6]. Salt is an ingredient of many high-fat and highenergy dense foods, so salt consumption may merely be incidental to the consumption of other ingredients that render individuals obese [7][8][9][10].…”