Title : Feeding efficiency of western and standard diets in Wister rats exercised with resistance training
Abstract:
The Western diet (WD), which is known by high daily intake of processed carbohydrates, saturated fats, and salt, has been associated with the development of several diseases, including cancer, atherosclerosis, dementia, and metabolic disorders. Excessive food consumption and sedentary lifestyle are the primary contributors for obesity. Along with nutritional counselling, exercise training is crucial in the management of overweight and obesity.
To evaluate the feeding efficiency of the western and standard diets in Wistar rats exercised (EX) with resistance training, twenty-eight female rats were divided into four groups (n=7): WD; WD+EX; Standard diet (SD); and SD+EX. Animals were supplied with water and food ad libitum. WD groups received a WD with 60% of total calories coming from fat, while groups SD received a standard maintenance laboratory diet. Body weight and food consumption were recorded every week, for 20 weeks. Exercised animals climbed a 1-meter-high homemade ladder, 8-12 dynamic movements/climb and 4-8 climbs/session, 3 days/week for 18 weeks. At the end of the experiment, the naso-anal length and the adipose tissue weight were measured. The amount of food consumed during the experiment, kcal ingested, Lee index, body mass index, specific rate of body mass gain, feed efficiency and the weight gain coefficient by caloric consumption were determined at this point. This experimental work was approved by the institutional and national ethical committees.
A gradual increase in the animals' body weight was observed throughout the study, which is associated with the animals’ normal growth. Body weight, as well as body mass index, specific rate of body mass gain, weight gain coefficient by caloric consumption, Lee index, adipose tissue weight and naso-anal length were not significantly different among groups (p>0.05). The amount of food eaten during all the experiment and Kcal ingested were higher in animals fed with a SD when compared with those fed with a WD (p<0.05). Inversely, the feed efficiency was higher in animals fed with a WD when compared with those fed with a SD (p<0.05). No differences were observed between sedentary and exercised animals (p>0.05).
The results suggested that the WD is probably associated with greater satiety, which is reflected in the consumption of smaller amounts of this type of food. The WD was also associated with a better feed efficiency. The resistance training did not influence any of the parameters evaluated.
