Fat brains, greedy genes, and parent power: A biobehavioural risk model of child and adult obesity

Abstract

We live in a world replete with opportunities to overeat highly calorifi c, palatable foods -yet not everyone becomes obese. Why? We propose that individuals show differences in appetitive traits (e.g. food cue responsiveness, satiety sensitivity) that manifest early in life and predict their eating behaviours and weight trajectories. What determines these traits? Parental feeding restriction is associated with higher child adiposity, pressure to eat with lower adiposity, and both strategies with less healthy eating behaviours, while authoritative feeding styles coincide with more positive outcomes. But, on the whole, twin and family studies argue that nature has a greater infl uence than nurture on adiposity and eating behaviour, and behavioural investigations of genetic variants that are robustly associated with obesity (e.g. FTO) confi rm that genes infl uence appetite. Meanwhile, a growing body of neuroimaging studies in adults, children and high risk populations suggests that structural and functional variation in brain networks associated with reward, emotion and control might also predict appetite and obesity, and show genetic infl uence. Together these different strands of evidence support a biobehavioural risk model of obesity development. Parental feeding recommendations should therefore acknowledge the powerful -but modifi able -contribution of genetic and neurological infl uences to children ' s eating behaviour.

External eating mediates the relationship between impulsivity and unhealthy food intake

“…One acknowledged contributing factor to the increasing rates of overweight and obesity over the last few decades is an "obesogenic" environment, where high caloric food is easily accessible and available (Hill et al, 2003). However, not all individuals overeat and/or gain weight indicating that there are differences in susceptibility to such an environment (Carnell et al, 2012). Recent evidence suggests that personality traits such as impulsivity may increase the likelihood of overeating in the face of such an environment, which in turn, can lead to weight gain.…”

All in the Family? Parental Roles in the Epidemic of Childhood Obesity

“…Researchers are now using bio-behavioral risk models to examine complex interactions among genetics, metabolic characteristics, and environment (Carnell, Kim and Pryor 2012). Not all individuals with these genetic propensities actually do become obese.…”

Flavour-enhanced cortisol release during gum chewing

“…The hedonic aspect of chewing is greatly affected by the taste and odour of food [2]. Chewing palatable foods (e.g., a gum with good taste and odour) can induce positive emotions [3]. The underlying neural mechanism of this phenomenon begins with detection via taste and odorant chemoreceptors [2].…”