Validation of a food frequency questionnaire in the assessment of dietary glycemic index, glycemic load, and protein intake in pregnant women with obesity

OBJECTIVES

Studies suggest that diets with a low glycemic index and high protein are favorable in aiding weight loss and improving weight maintenance; however, methods to measure dietary intake are comprehensive both for the participant and the study staff. We aimed to validate the accuracy of the dietary glycemic index and protein intake assessed through a food frequency questionnaire against a 4-d weighed food record in Danish pregnant women with obesity.

METHODS

A total of 31 pregnant women completed a 29-item food frequency questionnaire and a 4-d weighed food record with overlapping time periods. The women had a mean (± SD) age of 30.6 ± 3.9 y and a prepregnancy body mass index of 33.9 ± 3.5 kg/m2. We evaluated the validity of the food frequency questionnaire by Bland-Altman plots and the Spearman correlation coefficient.

RESULTS

The results of the validation study found good acceptance of the 29-item food frequency questionnaire. The mean intake of glycemic index, glycemic load, and protein intake of the 29-item food frequency questionnaire and the weighed food record correlated well, although intake data of the 29-item food frequency questionnaire tended to be lower. Spearman correlation coefficients had moderate to high correlations for glycemic index (ρ = 0.73; P < 0.001) and protein intake (ρ = 0.70; P < 0.001). A moderate correlation was found for glycemic load (ρ = 0.55; P = 0.002). There was no correlation for carbohydrates (ρ = 0.21; P = 0.253).

CONCLUSION

The results suggest no risk of bias between the two methods of assessment; hence, a 29-item food frequency questionnaire can be used to assess the mean glycemic index, glycemic load, and protein intake in pregnant women with obesity.

Gestational weight gain in women with pre-pregnancy overweight or obesity and anthropometry of infants at birth

Objective

To examine the association of gestational weight gain (GWG) among women with pre-pregnancy overweight or obesity with infant weight and BMI z-score at birth.

Methods

This study is a secondary analysis of a randomized controlled trial including data from 208 infants at birth born by mothers with pre-pregnancy BMI between 28 and 45 kg/m² who completed the APPROACH study (randomized to a high-protein low-glycemic index diet or a moderate-protein moderate-glycemic index diet). This analysis pooled the two diet treatment groups together and data were analyzed using a linear mixed model.

Results

Limiting GWG by 1 kg was associated with lower birthweight (-16 g, P = 0.003), BMI z-score (-0.03SD, P = 0.019), weight z-score (-0.03SD, P = 0.004), and infant abdominal circumference (-0.06 cm, P = 0.039). Infants born by mothers whose GWG was ≤9 kg weighed less (122 g, 95% CI: 6-249, P = 0.040), had similar BMI z-score (0.2SD, 95% CI: -0.06 to 0.55, P = 0.120), and lower incidence of emergency cesarean deliveries (11.5% vs. 23.1%, P = 0.044) compared to infants born by mothers whose GWG was >9 kg. When women were classified into GWG quartiles, women in Q1 (GWG range: -7.0 to 3.2 kg) gave birth to smaller infants (3,420 g, P = 0.015) with lower BMI z-score (-0.5SD, P = 0.041) than women in Q2 (3.3-7.1 kg), Q3 (7.2-10.9 kg) and Q4 (11.1-30.2 kg).

Conclusions

Limiting GWG among women with pre-pregnancy overweight or obesity was associated with lower infant weight, BMI z-score, weight z-score, and abdominal circumference at birth. Moreover, GWG below the Institute of Medicine guideline of a maximum of 9 kg was associated with lower birthweight and fewer emergency cesarean deliveries.

Timing and Frequency of Daily Energy Intake in Adults with Prediabetes and Overweight or Obesity and Their Associations with Body Fat

Knowledge on how energy intake and macronutrients are distributed during the day and the role of daily eating patterns in body composition among adults with overweight/obesity and prediabetes is lacking. Therefore, we evaluated the diurnal dietary intake and studied the associations of daily eating patterns with body fat percentage. A total of 119 adults with prediabetes were included (mean (SD) HbA_1c 41 (2.3) mmol/mol, BMI 31.5 (5.0) kg/m², age 57.8 (9.3) years, 44% men). Information on dietary intake was obtained from self-reported food records for three consecutive days. All foods and beverages (except water) were registered with information on time of ingestion. Body fat was measured by dual-energy X-ray absorptiometry. A total of 60.5% of the participants reported a daily eating window of 12 or more hours/day, and almost half of the daily total energy intake was reported in the evening. In analyses adjusted for age, gender, and total daily energy intake, having the first daily energy intake one hour later was associated with slightly higher body fat percentage (0.64% per hour, 95% CI: 0.28; 1.01; p < 0.001), whereas higher meal frequency was associated with slightly lower body fat percentage (0.49% per extra daily meal, 95% CI: −0.81; −0.18; p = 0.002). Prospective studies are warranted to address the clinical implications of daily eating patterns on body fat and cardiometabolic health.