Self-reported eating rate is associated with weight status in a Dutch population: a validation study and a cross-sectional study.

BACKGROUND: Observational studies performed in Asian populations suggest that eating rate is related to BMI. This paper investigates the association between self-reported eating rate (SRER) and body mass index (BMI) in a Dutch population, after having validated SRER against actual eating rate. METHODS: Two studies were performed; a validation and a cross-sectional study. In the validation study SRER (i.e., 'slow', 'average', or 'fast') was obtained from 57 participants (men/women = 16/41, age: mean ± SD = 22.6 ± 2.8 yrs., BMI: mean ± SD = 22.1 ± 2.8 kg/m2) and in these participants actual eating rate was measured for three food products. Using analysis of variance the association between SRER and actual eating rate was studied. The association between SRER and BMI was investigated in cross-sectional data from the NQplus cohort (i.e., 1473 Dutch adults; men/women = 741/732, age: mean ± SD = 54.6 ± 11.7 yrs., BMI: mean ± SD = 25.9 ± 4.0 kg/m2) using (multiple) linear regression analysis. RESULTS: In the validation study actual eating rate increased proportionally with SRER (for all three food products P < 0.01). In the cross-sectional study SRER was positively associated with BMI in both men and women (P = 0.03 and P < 0.001, respectively). Self-reported fast-eating women had a 1.13 kg/m2 (95% CI 0.43, 1.84) higher BMI compared to average-speed-eating women, after adjusting for confounders. This was not the case in men; self-reported fast-eating men had a 0.29 kg/m2 (95% CI -0.22, 0.80) higher BMI compared to average-speed-eating men, after adjusting for confounders. CONCLUSIONS: These studies show that self-reported eating rate reflects actual eating rate on a group-level, and that a high self-reported eating rate is associated with a higher BMI in this Dutch population.

Modeling of eating style and its effect on intake.

Observational research has indicated that modeling of eating style might occur when eating in the presence of an eating companion. This experiment investigated the effect of bite frequency of a same-sex eating companion on bite frequency, meal size and meal duration. A total of 30 normal weight young adults (m/f = 8/22, age: 21.2 ± 1.9 years, BMI: 21.2 ± 1.6 kg/m(2)) had three ad libitum meals together with a same-sex confederate (i.e. instructed eating companion). Confederates were instructed to eat at a slow (3 bites/min), medium (5 bites/min) or fast (7 bites/min) bite frequency in randomized order. Eating style was assessed through video registration and weighing left-overs. It was found that the participants' bite frequency was similar during all three conditions, i.e. slow: 3.9 ± 1.3, medium: 4.0 ± 1.1, fast: 4.0 ± 1.3 bites/min (p = 0.75), as was average bite size (11 ± 2.6 g). Time eaten of the participants was shorter in the medium (14.9 ± 3.6 min) and fast condition (14.4 ± 3.7 min) compared to the slow condition (16.8 ± 4.8 min) (post hoc in both cases p < 0.01), and intake was lower in the medium (634 ± 183 g) and fast condition (624 ± 190 g) compared to the slow condition (701 ± 220 g) (post hoc in both cases p < 0.05). This experimental study suggests that bite frequency is not affected by the confederate. However, the meal duration of the confederates showed a significant effect on the meal duration and meal size of the participants. It seems that intake was influenced as a result of copying meal termination.