Undervalued and ignored: Are humans poorly adapted to energy-dense foods?

Jeffrey M. Brunstrom*, Alex C.L. Drake, Ciarán G. Forde, Peter J. Rogers

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

41 Citations (Scopus)
781 Downloads (Pure)


In many species the capacity to accurately differentiate the energy density (kcal/g) of foods is critical because it greatly improves efficiency in foraging. In modern humans this ability remains intact and is expressed in a selective preference for types of fruit and vegetables that contain more calories. However, humans evolved consuming these low energy-dense foods (typically < 1.75 kcal/g) and it remains unclear whether they can also discriminate more energy-dense foods that now feature in modern Western diets. In two experiment participants (both N = 40) completed four tasks that assessed the ‘value’ of different sets of 22 foods that ranged in energy density (0.1 kcal/g–5.3 kcal/g and range 0.1 kcal/g to 6.2 kcal/g in Experiment 1 and 2, respectively). In Experiment 1 three measures (expected fullness, calorie estimation, and food choice), and in foods less than approximately 1.5 kcal/g (typically fruits and vegetables), the relationship between perceived value and energy density is linear. Above this, we observed clear compressive functions, indicating relative and progressive undervaluation of higher energy-dense foods. The fourth task (rated liking) failed to provide evidence for any relationship with energy density. In Experiment 2 the same pattern was replicated in measures of expected fullness, and in two different assessments of subjective calorie content. Consistent with the concept of ‘evolutionary discordance,’ this work indicates that modern human physiology is poorly adapted to evaluate foods that have a historically unusual (high) energy density. This has implications both for our understanding of how ‘modern’ energy-dense foods affect choice and energy intake, and for strategies aimed at removing calories from highly energy-rich foods.

Original languageEnglish
Pages (from-to)589-595
Number of pages7
Issue number1
Early online date14 Oct 2017
Publication statusPublished - 1 Jan 2018

Structured keywords

  • Brain and Behaviour
  • Nutrition and Behaviour
  • Physical and Mental Health


  • Diet
  • Energy density
  • Expected satiation
  • Food
  • Food choice
  • Nutrition
  • Obesity


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