RAMB - Setembro 2017

utritional

knowledge

and

body

mass

index

: A

cross

sectional

study

ssoc

ras

2017; 63(9):736-740

737

Patients who presented diseases that caused obesity

and water retention, presence of edema, liver disease or

nephropathy were excluded. Our study was approved by

the institution’s ethics committee.

Data collection procedure

Nutritional status was evaluated based on BMI, waist

circumference (WC) and the waist-hip ratio (WHR). In

order to measure weight and height, participants were

positioned on their feet, with their heels joined, arms

along their sides, legs stretched, shoulders relaxed, and

head in the horizontal plane; they were all barefoot and

wearing light clothing. Both height and weight were mea-

sured using an anthropometric scale, Filizola brand, lo-

cated in a private place, in the waiting room of the out-

patient clinic. WC was measured while the patient was

standing up, just after breathing out, 1 cm above the ili-

ac crest. Hip circumference was assessed on the widest

circumference of the buttocks. All of these measurements

were performed with an inelastic tape measure.

After the anthropometric evaluation, the patients

answered a questionnaire with thirteen questions. The

questionnaire was initially consisted of questions about

personal and sociodemographic identification, such as

sex, age, formal education, risk factors, food choice and

sources of food information. There were also 20 questions

to assess the level of general knowledge about food and

nutrition, such as sugar, fat, fiber and salt content in

foods, as well as sources of dietary cholesterol. The ques-

tionnaires were applied by a researcher trained for such

activity in the waiting room of the outpatient clinic.

The questionnaire was adapted from Parmenter and

Wardle,

since there were no other similar studies applied

in the adult Brazilian population. Questions about sourc-

es of information about foods and influences on food

choice were multiple choice, with the possibility of select-

ing more than one option for each of the questions, as well

as questions concerning sugar, fat and sodium contents

in foods. In all other questions about diet and nutrition,

patients could select only one of the alternatives presented.

Statistical analysis

The database was assembled using Excel 2003, while the

statistical analyzes were performed using SPSS software

version 17.0.2.

Means and standard deviation or median and mini-

mum and maximum values were used to present continu-

ous variables, while absolute (n) and relative (%) frequen-

cies were used for the categorical variables. Continuous

variables were analyzed using Pearson correlation, and

categorical variables were analyzed using Spearman cor-

relation. We used Student’s t-test to compare means, and

Chi-square test to analyze associations. In all comparisons,

a critical alpha of 0.05 was considered.

esults

The study totaled 263 participants. The sample was con-

sisted of 52% of female subjects, with 66.5% of married

individuals. Regarding education, 43.4% reported not

having completed elementary school. The mean age was

56.7 years and the mean BMI was in the obesity range

(32.48 kg/m

), as shown in Table 1. The general charac-

teristics of the population are presented in Table 1. BMI,

WC and WHR of both sexes are described in Table 2.

The mean of correct responses according to different

characteristics is described in Figure 1.

TABLE 1

General characteristics of the population.

Variables

N (%)

Female

138 (52.5)

Married

175 (66.5)

Elementary school, incomplete 114 (43.4)

High school diploma

70 (26.6)

N±SD

Mean age

56.7±12.9 years

Mean BMI

32.48±3.41 kg/m²

SD: standard deviation.

TABLE 2

Mean BMI, WC and WHR for men and women.

BMI (kg/m

) WC (cm)

WHR

Women

33.36±4.2

109.92±10.11 0.95±0.05

Men

32.26±2.1

112.57±7.43 1.00±0.05

Total of the sample 32.84±3.41 111.09±9.00 0.97±0.06

BMI: body mass index; WC: waist circumference; WHR: waist-hip ratio.

The BMI showed an inverse and significant association

with the percentage of correct answers (p=0.002), as well

as WC (p<0.001) and WHR (p<0.001). However, after

stratification by sex, there was a significant association

between women when correlating the percentage of cor-

rect answers with BMI (p<0.001) and WC (p<0.001).

Among men, there was a significant association between

the percentage of correct answers and WHR (p=0.002).

Regarding “dieting or adopting food restrictions,”

39.2% (103) answered affirmatively. Nevertheless, 88.2%

of the participants stated that they presented some CNCD

in addition to obesity.