title: Ability of self-reported estimates of dietary sodium, potassium and protein to detect an association with general and abdominal obesity: comparison with the estimates derived from 24 h urinary excretion.
abstract: As under-reporting of dietary intake, particularly by overweight and obese subjects, is common in dietary surveys, biases inherent in the use of self-reported dietary information may distort true diet-obesity relationships or even create spurious ones. However, empirical evidence of this possibility is limited. The present cross-sectional study compared the relationships of 24 h urine-derived and self-reported intakes of Na, K and protein with obesity. A total of 1043 Japanese women aged 18-22 years completed a 24 h urine collection and a self-administered diet history questionnaire. After adjustment for potential confounders, 24 h urine-derived Na intake was associated with a higher risk of general obesity (BMI≥25 kg/m2) and abdominal obesity (waist circumference≥80 cm; both P for trend=0·04). For 24 h urine-derived protein intake, positive associations with general and abdominal obesity were observed (P for trend=0·02 and 0·053, respectively). For 24 h urine-derived K intake, there was an inverse association with abdominal obesity (P for trend=0·01). Conversely, when self-reported dietary information was used, only inverse associations between K intake and general and abdominal obesity were observed (P for trend=0·04 and 0·02, respectively), with no associations of Na or protein intake. In conclusion, we found positive associations of Na and protein intakes and inverse associations of K intake with obesity when using 24 h urinary excretion for estimating dietary intakes. However, no association was observed based on using self-reported dietary intakes, except for inverse association of K intake, suggesting that the ability of self-reported dietary information using the diet history questionnaire for investigating diet-obesity relationships is limited.
authors.affiliation: Department of Nutrition,School of Human Cultures, University of Shiga Prefecture,Hikone,Shiga522 8533,Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Murakami
authors.affiliation: Northern Ireland Centre for Food and Health, University of Ulster,Coleraine,UK.
authors.forename: M Barbara E
authors.initials: MB
authors.lastname: Livingstone
authors.affiliation: Department of Social and Preventive Epidemiology,School of Public Health, University of Tokyo,Tokyo,Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Laboratory of Physiological Nutrition, Kagawa Nutrition University,Saitama,Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Uenishi
mesh_terms: D010129:4-Aminobenzoic Acid / Q000737:chemistry; D000293:Adolescent; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D005260:Female; D006801:Humans; D007564:Japan; D009765:Obesity / Q000652:urine*; D056128:Obesity, Abdominal / Q000097:blood*; D016017:Odds Ratio; D017419:Potassium, Dietary / Q000652:urine*; D057566:Self Report; D012964:Sodium / Q000737:chemistry; D012982:Sodium, Dietary / Q000008:administration & dosage*; D011795:Surveys and Questionnaires; D016482:Urinalysis; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D004044:Dietary Proteins; D017419:Potassium, Dietary; D012982:Sodium, Dietary; D012964:Sodium; D010129:4-Aminobenzoic Acid
keywords: Obesity