Quality More Than Quantity: The Use of Carbohydrates in High-Fat Diets to Tackle Obesity in Growing Rats

Abstract

Childhood obesity prevention is important to avoid obesity and its comorbidities into adulthood. Although the energy density of food has been considered a main obesogenic factor, a focus on food quality rather that the quantity of the different macronutrients is needed. Therefore, this study investigates the effects of changing the quality of carbohydrates from rapidly to slowly digestible carbohydrates on metabolic abnormalities and its impact on obesity in growing rats fed a high-fat diet (HFD). Growing rats were fed on HFD containing carbohydrates with different digestion rates: a HFD containing rapid-digesting carbohydrates (OBE group) or slow-digesting carbohydrates (ISR group), for 4 weeks and the effect on the metabolism and signaling pathways were analyzed in different tissues. Animals from OBE group presented an overweight/obese phenotype with a higher body weight gain and greater accumulation of fat in adipose tissue and liver. This state was associated with an increase of HOMA index, serum diacylglycerols and triacylglycerides, insulin, leptin, and pro-inflammatory cytokines. In contrast, the change of carbohydrate profile in the diet to one based on slow digestible prevented the obesity-related adverse effects. In adipose tissue, GLUT4 was increased and UCPs and PPARγ were decreased in ISR group respect to OBE group. In liver, GLUT2, FAS, and SRBP1 were lower in ISR group than OBE group. In muscle, an increase of glycogen, GLUT4, AMPK, and Akt were observed in comparison to OBE group. In conclusion, this study demonstrates that the replacement of rapidly digestible carbohydrates for slowly digestible carbohydrates within a high-fat diet promoted a protective effect against the development of obesity and its associated comorbidities.

Intake of slow-digesting carbohydrates is related to changes in the microbiome and its functional pathways in growing rats with obesity induced by diet

“…At the genus level, treatment of ISR after 4 weeks revealed a higher proportion of Alistipes compared to the NOB group, which might be a bacterial genus of particular interest in the field of obesity since Alistipes is a potential SCFA producer and it might play a role in reducing non-alcoholic steatohepatitis and/or liver fibrosis (53,54). Indeed, we observed a reduced hepatosteatosis in the OBE-ISR group with lower GLUT2, FAS, and SRBP1 (19). In addition, gut microbiota from the OBE-ISR group showed increased relative abundances of the genera Bifidobacterium, Bacteroides, Butyricimonas, Lachnoclostridium, Flavonifractor, Ruminiclostridium 5, and Faecalibaculum, indicating an improvement of these genera.…”

“…Nonetheless, the quality of CHO is crucial for optimal glycemic control, insulin response, and weight management (13,41,42). In that context, we have previously reported that the OBE-ISR group improves insulin sensitivity and reduces dyslipidemia in growing rats, as well as GLP-1 augmented levels (19). Using a well-established HFD rodent model of childhood diet-induced obesity, we evaluated the effects of a specialized CHO diet on the gut microbiota composition by comparing its quality rather than its quantity (rapid digestible vs. slowly digestible CHO).…”

“…Food and water were freely available to all rats, and their weight and food consumption were determined on a weekly basis. There has been previous publication on body composition, body fat mass, and lean body mass and metabolic parameters ( 19 ).…”

“…The TargetLynx application manager for MassLynx 4.1 (Waters Corp., Milford, MA, United States) was used to handle the data obtained with the aforementioned platform. The data obtained during the process were processed with R software v3.2.0 ( 19 ).…”

“…According to the previous research, slow-digesting CHOs (ISR) provide a number of metabolic benefits during growth and development as well as a reduction in the predisposition to obesity later in life ( 17 , 18 ). Recently, we have previously revealed that the replacement of rapid digestible CHO for slowly digestible CHO (ISR, containing isomaltulose, resistant maltodextrin, inulin, and FOS) in an HFD rat model prevented the diet-induced obesity-related adverse effects and improved lipid metabolism by different mechanisms in adipose tissue, muscle, and liver, which are related to modifications in key proteins, such as GLUT2 and GLUT4, FAS, SRBP1, AMPK, and Akt, among others ( 19 ). Currently, there are not enough basic studies analyzing microbial, metabolic, and inflammation data.…”