The role of phenotypic plasticity and palatability
Lean and colleagues article (1) on obesity fails to give sufficient acknowledgement to the role of palatability and phenotypic plasticity in the current obesity epidemic.
The high palatability of modern processed foods, to a large extent, is the consequence of added sugar (2,3). For example, fats and oils are relatively unpalatable but the addition of a small amount of sugar gives rise to a substantial increase in hedonic preference ratings (2) and therefore the likelihood of overconsumption.
Epigenetic transgenerational inheritance plays a role in evolutionary change (4,5,6) and is almost certainly a factor behind the apparent evolution of modern man in to a fatter “species” and obesity’s resistance to “treatment”.
The greatly enhanced palatability of the modern food environment is a significant environmental change and some behaviours of the obese appear to be adaptive to this new environment. For example, the obese have a lower preference for sweetness (7), under respond to food deprivation (8) and are more likely to skip meals (9). A recent study indicates that future generations also exposed to this obesogenic nutritional environment may have a lower risk of metabolic disorders also due to epigenetic adaptations (10).
I agree that the current epidemic will only be curtailed by regulation and taxation of the food environment but as epigenetic changes can persist through generations significant beneficial change may take more than one generation.
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9. Mota J, Fidalgo F, Silva R, Ribeiro JC, Santos R, Carvalho J, Santos MP. Relationship between physical activity, obesity and meal frequency in adolescents. Ann Hum Behav 2008;35(1):1-10.
10. Tait AH, Raubenheimer D, Green MP, Cupido CL, Gluckman PD, Vickers MH. Successive Generations in a Rat Model Respond Differently to a Constant Obesogenic Environment. PLoS ONE 2015;10(7):e0129779.
Competing interests: No competing interests