Failed to replicate previous nonrandomized observational studies, which had suggested that ratings of female physical attractiveness by males are sensitive to the levels of hunger

No impact of hunger on male perception of female physical attractiveness in relation to adiposity: a randomized controlled trial. Z. Jin, G. Wang, S. Hu & J. R. Speakman . International Journal of Obesity (2019), June 17 2019. https://www.nature.com/articles/s41366-019-0392-2

Abstract
Background: Female physical attractiveness is strongly related to body mass index (BMI). Females with lower BMI are on average more attractive down to at least BMI = 18. Previous correlational studies have indicated that this effect may be modulated by the hunger of the rater, with more hungry raters preferring images of subjects with greater adiposity. This prior work, however, was correlational and so we wished to explore this phenomenon further using a randomized controlled trial.

Methods and subjects: Two studies are presented. In the first, 52 male participants were recruited and after an overnight fast were randomly allocated to either fed or starved treatments. Starved individuals continued not to feed, while fed individuals were given ad libitum access to foods and were encouraged to eat to full satiation. Their hunger levels were monitored using visual analog scales (VAS) and levels of circulating glucose. Four hours later, they were asked to complete a previously used female attractiveness rating test, a standard IQ test, and a memory recall test. In the second study, which was a double-blind experiment, 32 individuals were recruited to evaluate if the original effect was due to a confounding impact of alcohol consumption when dining. Blinded individuals consumed drinks with or without alcohol. Their circulating alcohol levels were quantified by a breath test, and they repeated the tests matched with the first study excluding the IQ test.

Results: Hunger resulted in lower performance on the memory recall test, but had no effect on the IQ score, and contrasting previous results had no effect on the ratings of female physical attractiveness. Circulating alcohol levels had no effect on the memory recall test, but there was a significant negative relationship between circulating alcohol and the mean adiposity of the five individuals rated as least attractive.

Conclusions: This randomized controlled trial failed to replicate previous nonrandomized observational studies, which had suggested that ratings of female physical attractiveness by males are sensitive to the levels of hunger. The reason for the difference was possibly because in previous studies, levels of hunger were confounded by alcohol consumption.