Abstract
Among adolescents, overweight, obesity and metabolic syndrome are rapidly increasing in recent years as a consequence of unhealthy palatable diets. Animal models of diet-induced obesity have been developed, but little is known about the behavioural patterns produced by the consumption of such diets. The aim of the present study was to determine the behavioural and biochemical effects of a cafeteria diet fed to juvenile male and female rats, as well as to evaluate the possible recovery from these effects by administering standard feeding during the last week of the study. Two groups of male and female rats were fed with either a standard chow diet (ST) or a cafeteria (CAF) diet from weaning and for 8 weeks. A third group of males (CAF withdrawal) was fed with the CAF diet for 7 weeks and the ST in the 8th week. Both males and females developed metabolic syndrome as a consequence of the CAF feeding, showing overweight, higher adiposity and liver weight, increased plasma levels of glucose, insulin and triglycerides, as well as insulin resistance, in comparison with their respective controls. The CAF diet reduced motor activity in all behavioural tests, enhanced exploration, reduced anxiety-like behaviour and increased social interaction; this last effect was more pronounced in females than in males. When compared to animals only fed with a CAF diet, CAF withdrawal increased anxiety in the open field, slightly decreased body weight, and completely recovered the liver weight, insulin sensitivity and the standard levels of glucose, insulin and triglycerides in plasma. In conclusion, a CAF diet fed to young animals for 8 weeks induced obesity and metabolic syndrome, and produced robust behavioural changes in young adult rats, whereas CAF withdrawal in the last week modestly increased anxiety, reversed the metabolic alterations and partially reduced overweight.
Highlights
In recent decades, the prevalence rates of paediatric overweight and obesity have been increasing, reaching 20% or more in some countries [1,2]
The present study shows that a palatable CAF diet administered from weaning to male and female rats increased food and fluid consumption, induced body weight gain, increased adiposity and liver weight, and produced different metabolic disturbances strongly related with the development of the metabolic syndrome, such as hypertriglyceridemia, hyperglycaemia and insulin resistance
These results are in line with the reported sex-associated differences in the regulation of proteins controlling body weight [25], and with the gender differential metabolic responses to the consumption of a palatable diet found after administering distinct forms of early stress to the animals [26,27]
Summary
The prevalence rates of paediatric overweight and obesity have been increasing, reaching 20% or more in some countries [1,2]. Animal models developed to induce obesity in rodents are usually based on different forms of diet containing high fat, high sugar or palatable foods regularly consumed by humans. Among such diets, the cafeteria (CAF) diet has been shown to consistently increase body weight, induce hyperphagia and alter the metabolic factors clustered in the metabolic syndrome [5,6]. Administration of the CAF diet for 15 days to young adult male and female rats increased adiposity and decreased adiponectin production in white adipose tissue, whereas the levels of insulin in plasma, insulin sensitivity and body weight did not change in males [7]. The CAF diet administered to female rats, from weaning to adulthood, induced obesity by increasing body and fat pad weight, resulting in increased levels of triglycerides, total cholesterol and LDLcholesterol, as well as induced insulin resistance and reproductive deficits [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
