Impact of a cafeteria diet and daily physical training on the rat serum metabolome

Abstract

Regular physical activity and healthy dietary patterns are commonly recommended for the prevention and treatment of metabolic syndrome (MetS), which is diagnosed at an alarmingly increasing rate, especially among adolescents. Nevertheless, little is known regarding the relevance of physical exercise on the modulation of the metabolome in healthy people and those with MetS. We have previously shown that treadmill exercise ameliorated different symptoms of MetS. The aim of this study was to investigate the impact of a MetS-inducing diet and different intensities of aerobic training on the overall serum metabolome of adolescent rats. For 8 weeks, young rats were fed either standard chow (ST) or cafeteria diet (CAF) and were subjected to a daily program of training on a treadmill at different speeds. Non-targeted metabolomics was used to identify changes in circulating metabolites, and a combination of multivariate analysis techniques was implemented to achieve a holistic understanding of the metabolome. Among all the identified circulating metabolites influenced by CAF, lysophosphatidylcholines were the most represented family. Serum sphingolipids, bile acids, acylcarnitines, unsaturated fatty acids and vitamin E and A derivatives also changed significantly in CAF-fed rats. These findings suggest that an enduring systemic inflammatory state is induced by CAF. The impact of physical training on the metabolome was less striking than the impact of diet and mainly altered circulating bile acids and glycerophospholipids. Furthermore, the serum levels of monocyte chemoattractant protein-1 were increased in CAF-fed rats, and C-reactive protein was decreased in trained groups. The leptin/adiponectin ratio, a useful marker of MetS, was increased in CAF groups, but decreased in proportion to training intensity. Multivariate analysis revealed that ST-fed animals were more susceptible to exercise-induced changes in metabolites than animals with MetS, in which moderate-intensity seems more effective than high-intensity training. Our results indicate that CAF has a strong negative impact on the metabolome of animals that is difficult to reverse by daily exercise.

Impact of Cafeteria Diet on the Composition of Fatty Acids in Zebrafish (Danio rerio) Fillets

“…The CAF diet presented higher total lipid (32.36 ± 4.77%) and energy (539.34 ± 23.99%) values than the ST diet, due to the addition of peanut, chocolate and biscuit in its preparation, foodstuffs with high fat/energy. 22,23 It was observed that the CAF diet presented a higher proportion of fat in its composition when compared to the ST diet; this was also observed in studies conducted by Zeeni et al, 2 Suárez-García et al 24 and Cardoso et al 25 In our study, peanut, chocolate and biscuit were used to increase the caloric density of the CAF diet; other studies used bacon, 10 sweet roll 24 and peanut butter. 2 Although the basis of all CAF diets is high fat and calories, their composition is very different, not having a standard regarding the amount and composition of the food.…”

“…The CAF diet decreased the omega-3 polyunsaturated fatty acid (n-3 PUFA) content 0.5 times in zebrafish fillets, from 2.62 (0 days of supplementation) to 1.39 mg g -1 (60 days of supplementation). Suárez-García et al 24 observed a reduction of n-3 PUFA levels (alpha-linolenic acid and docosahexaenoic acid) in female Sprague-Dawley rats as a result of the ingestion of the CAF diet. This is explained because long-chain n-3 PUFAs decrease the production of pro-inflammatory eicosanoids from arachidonic acid and increase the production of anti-inflammatory eicosanoids with the objective of resolving acute inflammation.…”

“…These associations have also been demonstrated in animal studies. 2,10,24,25 One of the key factors driving the worldwide rise in obesity is related to changes in eating habits, including increased energy-dense foods. In this context, the CAF diet model induces obesity in animals using high-caloric foods in order to reflect the eating habits of Western societies that have relevance in increasing obesity in humans.…”

Effects of an Intermittent Grape-Seed Proanthocyanidin (GSPE) Treatment on a Cafeteria Diet Obesogenic Challenge in Rats

“…However, it can be clearly seen that the time when it is administered in relation to the time-course of a cafeteria diet is also very important [ 35 ]. Body weight gain and adiposity are clearly found after 5 or 8 weeks of a cafeteria diet [ 36 ]. Hypertriglyceridemia has been observed from the 4th week of a cafeteria diet in hamsters [ 25 ] and after 8 weeks in rats [ 36 ]; however, hypercholesterolemia needs a longer treatment time to show clearly significant increases—around 13 weeks of a cafeteria diet [ 16 ].…”

“…Body weight gain and adiposity are clearly found after 5 or 8 weeks of a cafeteria diet [ 36 ]. Hypertriglyceridemia has been observed from the 4th week of a cafeteria diet in hamsters [ 25 ] and after 8 weeks in rats [ 36 ]; however, hypercholesterolemia needs a longer treatment time to show clearly significant increases—around 13 weeks of a cafeteria diet [ 16 ]. Changes in glucose tolerance start at week 7, according to Sampey and colleagues [ 12 ], with an increase in glycemia after 15 weeks.…”