Alternative methods of accounting for underreporting and overreporting when measuring dietary intake-obesity relations

Underreporting of energy intake in maintenance hemodialysis patients: a cross-sectional study

OBJECTIVE

To analyze the reported energy intake (EI(rep)) in hemodialysis (HD) patients by total energy expenditure (TEE) measured by a dedicated device.

DESIGN

Cross-sectional study.

SETTING

RenalCor and RenalVida Clinics (Rio de Janeiro, Brazil).

PATIENTS AND OTHERS PARTICIPANTS

Forty-eight HD patients (51.4 ± 12.2 years, 62% men, body mass index [BMI], 23.8 ± 4.5 kg/m(2)) were studied.

MAIN OUTCOME MEASURE

EI(rep) was evaluated using a 3-day food record. TEE was measured over a 2-day period by SWA (SenseWear Pro2 Armband, BodyMedia Inc., Pittsburgh, PA). Subjects were identified as underreporters (URs), acceptable reporters (ARs), or overreporters (ORs) from their EI(rep)/TEE ratio. ARs were defined as having the EI(rep)/TEE ratio in the range of 0.76 to 1.24, URs as EI(rep)/TEE <0.76, ORs as EI(rep)/TEE >1.24 according to Goldberg index.

RESULTS

The mean TEE and EI(rep) were 34.7 ± 9.4 kcal/kg/day and 22.8 ± 10.6 kcal/kg/day, respectively, and 37.5% of patients presented overweight or obesity. Thirty-one patients (65%) were identified as URs, and the mean of Goldberg index was 0.54 ± 0.12 (0.23 to 0.75), versus 0.95 ± 0.12 (0.79 to 1.2) for ARs. There were no ORs among the patients studied. There were negative correlations between Goldberg index and BMI (r = -0.35, P < .01) and % body fat (r = -0.4, P < .01) and between EI(rep) and BMI (r = -0.58, P < .001).

CONCLUSION

These results confirm a high prevalence of underreporting of EI in HD patients, particularly in patients with high BMI.

Olive oil consumption, BMI, and risk of obesity in Spanish adults

BACKGROUND

Olive oil is an energy-dense food frequently consumed in south European countries with increasingly high obesity prevalence. Evidence of the impact of olive oil consumption on BMI and the risk of obesity is limited. We analyzed this association taking into consideration the problem of energy underreporting.

METHODS

Cross-sectional data on 6,352 Spanish adults were analyzed. Dietary intake was assessed using a validated food frequency questionnaire. Height and weight were measured.

RESULTS

Higher olive oil consumption was not associated with energy compensation in the overall diet. Olive oil consumption was positively associated (p < 0.004) with BMI in non-energy-adjusted multivariate linear regression models. Statistical significance of this association disappeared after controlling for energy intake in plausible energy intake reporters. The obesity risk increased for olive oil consumption of more than 2 tablespoons/day in both plausible energy intake reporters (odds ratio 1.30 (95% CI 1.01-1.70)) and energy intake underreporters (odds ratio 3.06 (95% CI 2.15-4.35)). This association was not significant after additional adjustment for energy intake (odds ratio 1.19 (95% CI 0.91-1.56)) in plausible energy intake reporters.

CONCLUSION

Olive oil intake did not affect BMI and the risk of obesity after adjustment for total energy intake in plausible energy intake reporters. The lack of energy intake compensation for olive oil consumption might explain the positive associations in models not adjusted for energy.

Vitamin C and fibre consumption from fruits and vegetables improves oxidative stress markers in healthy young adults

The aim of the present cross-sectional study was to assess the potential relationships between fruit and vegetable (FV) consumption and some oxidative stress markers in young adults, with particular emphasis on fibre and vitamin C intake. The study enrolled 246 healthy subjects (eighty-eight men and 158 women), with a mean age of 22 (sd 3) years and a mean BMI of 21·9 (sd 2·8) kg/m2. Dietary intake, anthropometry, blood pressure, lifestyle features and blood biochemical data were assessed with validated procedures. Those subjects in the highest tertile (T) of FV consumption ( ≥ 705 g/d) had statistically lower oxidised LDL (ox-LDL) concentrations as well as higher plasma total antioxidant capacity (TAC) and glutathione peroxidase (GPx) activity (P for trend <0·05), after adjusting for sex, age, energy intake, physical activity, smoking, BMI, vitamin supplement use and other confounding factors. Moreover, plasma ox-LDL concentrations showed a decreasing trend and TAC an increasing trend across tertiles of fibre (T3: ≥14 g/d) and vitamin C (T3: ≥150 mg/d) from FV intake, while GPx activity was positively associated with vitamin C intake (P for trend < 0·05). In conclusion, greater FV consumption was independently associated with reduced ox-LDL as well as increased TAC and GPx activity in healthy young adults, with dietary fibre and vitamin C from FV clearly being implicated in this beneficial relationship.