Background: Controlling eating rate may be a mechanism for reducing calorie consumption. We need to understand the physiological basis of this to design effective paediatric interventions.
Objective and hypotheses: This study investigated the effect of eating rate during lunch on post-meal neural response (fMRI), satiety hormone levels, appetite ratings (VAS), meal enjoyment, memory for recent eating and snack consumption.
Method: Twenty young people (mean age 23.0 years, normal BMI) were randomly assigned to consume 600 kcal at a normal or slow rate (6 vs 24 mins). fMRI was performed at baseline and 2 hours post-meal, including a memory task about the lunch. Appetite ratings and satiety hormone levels (PYY and ghrelin) were collected at baseline and change recorded half-hourly for 3 hours. Participants were given an ad-libitum snack 3 hours post-meal.
Results: Relative to the slow group, immediately post-meal, the normal group reported greater fullness (effect size=−0.2), enjoyed the meal more (effect size=−0.5) and found it more satisfying (effect size=−0.6). However, 2 hours post-meal the slow group reported greater fullness (effect size=0.7), scored higher on portion size memory task (M=79%, vs M=68%, effect size=0.4), showed greater activation in the medial temporal lobe, and ate fewer snacks (M=341.8 kcal, vs M=445.4 kcal; effect size=0.5). Ghrelin secretion was lower in the slow group than the normal group at 30 and 120 minutes post-meal (effect size=−0.8). Ghrelin levels at 180 minutes were correlated with ad-libitum intake (r=0.590, P=0.013). At 30 minutes, PYY levels were correlated with enjoyment of the meal (r=0.451, P=0.046) and positively associated with memory task activation in the precuneus, striatum and insula.
Conclusion: Eating slowly improved memory for the meal, increased satiety and led to 25% less snacks eaten, but reduced ghrelin levels and enjoyment of the meal. Research is planned to confirm that these findings persist in the paediatric population.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology