Canaries in the coal mine: a cross-species analysis of the plurality of obesity epidemics

Abstract

A dramatic rise in obesity has occurred among humans within the last several decades. Little is known about whether similar increases in obesity have occurred in animals inhabiting human-influenced environments. We examined samples collectively consisting of over 20 000 animals from 24 populations (12 divided separately into males and females) of animals representing eight species living with or around humans in industrialized societies. In all populations, the estimated coefficient for the trend of body weight over time was positive (i.e. increasing). The probability of all trends being in the same direction by chance is 1.2 Â 10 27 . Surprisingly, we find that over the past several decades, average mid-life body weights have risen among primates and rodents living in research colonies, as well as among feral rodents and domestic dogs and cats. The consistency of these findings among animals living in varying environments, suggests the intriguing possibility that the aetiology of increasing body weight may involve several as-of-yet unidentified and/or poorly understood factors (e.g. viral pathogens, epigenetic factors). This finding may eventually enhance the discovery and fuller elucidation of other factors that have contributed to the recent rise in obesity rates.

The human obesity epidemic, the mismatch paradigm, and our modern “captive” environment

“…Obesity is also a significant problem among animals that humans keep in captivity. Both companion animals, laboratory animals, and animals kept in zoological parks have seen increases in obesity prevalence (Klimentidis et al, 2011). My colleague Suzette Tardif and I have investigated the development of obesity in a colony of captive marmosets.…”

Importance of Dietary Fatty Acid Profile and Experimental Conditions in the Obese Insulin-Resistant Rodent Model of Metabolic Syndrome

“…Animal feeds were also subject to the change from a low to high omega-6 content with the incorporation of vegetable oils, and this has led to and increase in obesity in domestic and laboratory animals [5]. Laboratory animals, whose housing and husbandry practices have no changed much in the last 50 years, now have a much increased mid-life bodyweight.…”

“…This risk of developing obesity and T2D has largely been blamed on the increased consumption of energy dense foods and fat intake, particularly saturated fat, but it is interesting to know that the mean fat intake of the human population has not increased m u c h i n t h e p a s t 5 0 y e a r s [ 4 ] . I t i s t r u e that the vast advancement in technological developments has led to a reduction in physical activity worldwide, but as obesity now involves infants and the populations of developing countries [5], this obesity pandemic cannot be attributed to this alone. In addition, laboratory and other domesticated animals have also been subject to the increased prevalence of obesity, despite having largely unchanged living conditions for many years [5].…”

“…I t i s t r u e that the vast advancement in technological developments has led to a reduction in physical activity worldwide, but as obesity now involves infants and the populations of developing countries [5], this obesity pandemic cannot be attributed to this alone. In addition, laboratory and other domesticated animals have also been subject to the increased prevalence of obesity, despite having largely unchanged living conditions for many years [5].…”

Primate aging in the mammalian scheme: the puzzle of extreme variation in brain aging

“…At present, there is little standardization among captive colonies of any species in either diet or social environments. Obesity is rampant in captive mammals of virtually all species, and primates are no exception (Hotta et al 1996;Klimentidis et al 2011;Steinetz et al 1996). A significant challenge is to define healthy (normative) body weight or body mass index for the common research primates.…”