Eating rate is a heritable phenotype related to weight in children.
BACKGROUND
There is growing interest in the heritability of behavioral phenotypes related to adiposity. One potential candidate is the speed of eating, although existing evidence for an association with weight is mixed.


OBJECTIVE
We aimed to assess the speed of eating in a sample of 10-12-y-old children to test the hypotheses that higher eating rate is related to greater adiposity and that eating rate is a heritable characteristic.


METHODS
Video data of 254 twin children eating a standard meal at home were used to record eating rate (bites/min) and changes in eating rate across the 4 quarters of the meal. Adiposity was indexed with body mass index SD scores relative to British 1990 norms; for some analyses, children were categorized into groups of overweight or obese and into 2 subgroups of normal-weight (lower normal-weight or higher normal-weight) for comparison of the eating rate within the normal range as well as between clinical and nonclinical groups. All analyses controlled for clustering in twin pairs. Heritability of eating rate was modeled by using standard twin methods.


RESULTS
There was a significant linear association across the 3 weight groups for eating rate (P = 0.010), and regression analyses showed that eating rate increased by 0.18 bites/min for each 1-unit increase in body mass index SD score (P = 0.005). The heritability of eating rate was high (0.62; 95% CI: 0.45, 0.74). There was no association between weight group and a change (ie, deceleration) in eating rate over the mealtime.


CONCLUSIONS
Faster eating appears to be a heritable behavioral phenotype related to higher weight.
Llewellyn
Clare H
CH
Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, United Kingdom.
van Jaarsveld
Cornelia H M
CH
Boniface
David
D
Carnell
Susan
S
Wardle
Jane
J
D050154:Adiposity / Q000502:physiology; D000704:Analysis of Variance; D000886:Anthropometry; D015992:Body Mass Index; D002648:Child; D002652:Child Behavior / Q000502:physiology*; D002664:Child Nutritional Physiological Phenomena / Q000502:physiology*; D004435:Eating / Q000235:genetics* / Q000502:physiology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000209:etiology / Q000235:genetics / Q000517:prevention & control; D010641:Phenotype; D012044:Regression Analysis; D013997:Time Factors; D014741:Video Recording; D015430:Weight Gain / Q000235:genetics* / Q000502:physiology*