Alteration of food consumption and body mass of whey proteins supplemented rats

Introduction: Whey proteins have received great attention because of their benefits on skeletal muscle hypertrophy, body fat reduction, performance, appetite regulation, immune system regulation, regulation of the lipid profile and the combat against metabolic stress. In this sense, their importance is often overestimated, leading athletes and physical activity individuals to consume very high doses of protein, without the guarantee of additional benefits.  Aim: For 12 weeks quantify the evolution of food intake and total body mass of Wistar rats supplemented with whey proteins with dosages of 2, 4, 6g/kg/day. Materials and methods: Approval protocol of the Ethics Committee on the Use of Animals of the Federal University of Maranhão nº 23115.014424 / 2015-54). An experimental research design was adopted with the rats being randomly distributed in 4 groups: Control Group (C), Supplemented groups (W2, W4, W6); the study was performed with 38 male Rattus novergicus Wistar rats with initial age of 60 days and body mass between 218 and 323 grams; supplementation with whey proteins dissolved in water followed the dosages 2, 4 and 6 g / kg / day supplementation was performed for 12 weeks, daily, three times a day, by volume of 5 ml, with an hour interval between each gavage. Variables were tested for distribution using the Shapiro-Wilk test (P> 0.05). The data of the feed consumption were analyzed by the ANOVA test; the classification variable was the interaction between feed consumption or body mass and supplementation (C, W2, W4, W6); the Tukey post-test was used to determine the statistical differences between the groups (C, W2, W4, W6), GraphPad Prism 7 software was used. Results: The mean intake of rations in the control group did not present a statistically significant difference in relation to the Whey 4 group at weeks 1 (p=0,3450), 2 (p=0,1027), 3 (p=0,1595), 4 (p=0,5572) and 5 (p=0,2539). There was a statistically significant difference in the increase of the total body mass of the control group compared to the Whey 4 group at weeks 10 (p=0,0454), 12 (p=0,0348) and at the final week (p=0,0138). Likewise, there was a significant statistical difference in the increase of the total body mass of the control group compared to the Whey group 6 in the final week (p=0,0048). In the same sense, there was a statistically significant difference in the total body mass increase of the Whey 2 group compared to the Whey 6 group in weeks 1 (p=0,0210), 2 (p=0,0434) and in the final week (p=0,0289). Discussion: Diets with high protein content play an important role in satiety due to its involvement with intestinal production of several anorectic hormones, which in turn stimulate the vagus nerve, promoting neuronal stimuli to the solitary tract nucleus, signaling satiety. As a result, the long-term ingestion of a high-protein diet reduces not only food intake, but also body mass and body adiposity in rats. Conclusion: Supplementation with serum whey proteins at doses of 4 and 6 g/kg/day in sedentary animals conferred stability over total body weight and a significant reduction in feed intake over 12 weeks. Supplementation with serum whey proteins at 2 g/kg/day in sedentary animals did not lead to a reduction in the average feed intake and showed a similar effect to the other doses on total body weight

Alteração da massa corporal e do consumo alimentar de ratos suplementados com whey proteins

Introduction: Whey proteins have received great attention because of their benefits on skeletal muscle hypertrophy, body fat reduction, performance, appetite regulation, immune system regulation, regulation of the lipid profile and the combat against metabolic stress. In this sense, their importance is often overestimated, leading athletes and physical activity individuals to consume very high doses of protein, without the guarantee of additional benefits.  Aim: For 12 weeks quantify the evolution of food intake and total body mass of Wistar rats supplemented with whey proteins with dosages of 2, 4, 6g/kg/day. Materials and methods: Approval protocol of the Ethics Committee on the Use of Animals of the Federal University of Maranhão nº 23115.014424 / 2015-54). An experimental research design was adopted with the rats being randomly distributed in 4 groups: Control Group (C), Supplemented groups (W2, W4, W6); the study was performed with 38 male Rattus novergicus Wistar rats with initial age of 60 days and body mass between 218 and 323 grams; supplementation with whey proteins dissolved in water followed the dosages 2, 4 and 6 g / kg / day supplementation was performed for 12 weeks, daily, three times a day, by volume of 5 ml, with an hour interval between each gavage. Variables were tested for distribution using the Shapiro-Wilk test (P> 0.05). The data of the feed consumption were analyzed by the ANOVA test; the classification variable was the interaction between feed consumption or body mass and supplementation (C, W2, W4, W6); the Tukey post-test was used to determine the statistical differences between the groups (C, W2, W4, W6), GraphPad Prism 7 software was used. Results: The mean intake of rations in the control group did not present a statistically significant difference in relation to the Whey 4 group at weeks 1 (p=0,3450), 2 (p=0,1027), 3 (p=0,1595), 4 (p=0,5572) and 5 (p=0,2539). There was a statistically significant difference in the increase of the total body mass of the control group compared to the Whey 4 group at weeks 10 (p=0,0454), 12 (p=0,0348) and at the final week (p=0,0138). Likewise, there was a significant statistical difference in the increase of the total body mass of the control group compared to the Whey group 6 in the final week (p=0,0048). In the same sense, there was a statistically significant difference in the total body mass increase of the Whey 2 group compared to the Whey 6 group in weeks 1 (p=0,0210), 2 (p=0,0434) and in the final week (p=0,0289). Discussion: Diets with high protein content play an important role in satiety due to its involvement with intestinal production of several anorectic hormones, which in turn stimulate the vagus nerve, promoting neuronal stimuli to the solitary tract nucleus, signaling satiety. As a result, the long-term ingestion of a high-protein diet reduces not only food intake, but also body mass and body adiposity in rats. Conclusion: Supplementation with serum whey proteins at doses of 4 and 6 g/kg/day in sedentary animals conferred stability over total body weight and a significant reduction in feed intake over 12 weeks. Supplementation with serum whey proteins at 2 g/kg/day in sedentary animals did not lead to a reduction in the average feed intake and showed a similar effect to the other doses on total body weight.Introdução: As whey proteins tem recebido grande atenção por conta de seus benefícios sobre a hipertrofia muscular esquelética, redução de gordura corporal, performance, regulação do apetite, regulação do sistema imunológico, regulação do perfil lipídico e combate ao estresse metabólico. Diante disso, a sua importância muitas vezes é superestimada, levando atletas e indivíduos praticantes de atividades físicas a consumirem doses muito elevadas de proteínas, sem a garantia de benefícios adicionais. Objetivo: Quantificar durante 12 semanas a alteração do consumo de ração e da massa corporal total de ratos wistar suplementados por whey proteins nas doses de 2, 4, 6g/kg/dia. Materiais e Métodos: Protocolo de aprovação da Comissão de Ética no Uso de Animais da Universidade Federal do Maranhão nº 23115.014424/2015-54). Foi adotado delineamento de pesquisa experimental com os ratos sendo distribuídos aleatoriamente em 4 grupos: Grupo Controle (C), Grupos suplementados (W2, W4, W6); o estudo foi realizado com 38 Rattus novergicus machos da linhagem Wistar com idade inicial de 60 dias e massa corporal entre 218 e 323 gramas; a suplementação com whey proteins dissolvidas em água seguiu as dosagens 2, 4 e 6 g/kg/dia a suplementação foi realizada durante 12 semanas, diariamente, três vezes por dia, em volume de 5ml, com uma hora de intervalo entre cada gavagem. As variáveis ​​foram testadas quanto à distribuição utilizando o teste de Shapiro-Wilk (p>0,05). Os dados do consumo de ração, foram analisados pelo teste ANOVA; a variável de classificação foi a interação entre o consumo de ração ou massa corporal e a suplementação (C, W2, W4, W6); o pós-teste de Tukey foi utilizado para determinar as diferenças estatísticas entre os grupos (C, W2, W4, W6), utilizou-se o software GraphPad Prism 7. Resultados: A média de consumo de ração no grupo controle não apresentou diferença estatística significativa em relação ao grupo Whey 4 nas semanas 1 (p=0,3450), 2 (p=0,1027), 3 (p=0,1595), 4 (p=0,5572) e 5 (p=0,2539). Houve diferença estatística significativa no aumento da massa corporal total do grupo controle em comparação ao grupo Whey 4 nas semanas 10 (p=0,0454), 12 (p=0,0348) e na semana final (p=0,0138). Do mesmo modo, houve diferença estatística significativa no aumento da massa corporal total do grupo controle em comparação ao grupo Whey 6 na semana final (p=0,0048). Nesse mesmo sentido, houve diferença estatística significativa no aumento massa corporal total do grupo Whey 2 em comparação ao grupo Whey 6 nas semanas 1 (p=0,0210), 2 (p=0,0434) e na semana final (p=0,0289). Discussão: Dietas com altos teores de proteínas desempenham um papel importante no surgimento da saciedade em função do seu envolvimento com a produção a nível intestinal de diversos hormônios anorexígenos que por sua vez estimulam o nervo vago, promovendo estímulos neuronais para o núcleo trato solitário, sinalizando saciedade. Em função disso, a ingestão a longo prazo de uma dieta rica em proteínas diminui não só a ingestão de alimentos, mas também a massa corporal e a adiposidade corporal em ratos. Conclusão: A suplementação com as proteínas do soro do leite nas doses de 4 e 6g/kg/dia em ratos sedentários conferiram estabilidade em relação a massa corporal total e redução significativa do consumo de ração ao longo de 12 semanas. A suplementação com as proteínas do soro do leite na dose de 2g/kg/dia em ratos sedentários não promoveu redução no consumo médio de ração e apresentou efeito semelhante as demais doses sobre a massa corporal total