Ketogenic diets in weight loss: a systematic review under physiological and biochemical aspects of nutrition

Abstract

Countless strategies have been proposed to change dietary patterns to promote weight loss. Many of these strategies are controversial, with questions of effectiveness and possible negative consequences to health, even if weight loss effects are achieved. Ketogenic diets, with or without calorie restrictions, are framed in this context. In the present systematic review, evidence on ketogenic diets for weight loss was investigated. Studies on ketogenic diet with or without calorie restriction related to weight loss published between 2012 and 2017 were selected from MEDLINE, Scielo and Web of Science databases. Results show there is a lack of knowledge on specific physiological mechanisms involved in the ketogenic diet. Much of the evidence published, despite showing specific effects on weight loss, BMI and fat percentage reduction, did not precisely assess its effects on specific physiological and biochemical parameters, mainly on the hepatic, cardiac and renal tissues. We conclude that strategies to control overweight and obesity do not necessarily need to impose restrictions on certain nutrients, especially carbohydrates, or increase the intake of food groups whose excessive consumption has been associated with different pathologies. RESUMENInnumerables estrategias se han propuesto para cambiar el patrón de la dieta y así promover la pérdida de peso. Muchas de estas estrategias aún son controversiales con respecto a la efectividad y las consecuencias negativas para la salud. Las dietas cetogénicas, con o sin restricciones calóricas, se enmarcan en este contexto. En la presente revisión sistemática, se investigaron las evidencias sobre las dietas cetogénicas para la pérdida de peso. Para esto, se seleccionaron los estudios de dieta cetogénica con o sin restricción calórica relacionada con la pérdida de peso publicados entre 2012 y 2017 a través de las bases de datos MEDLINE, Scielo y Web of Science. Los resultados muestran falta de conocimiento sobre mecanismos fisiológicos específicos implicados en la dieta cetogénica. Gran parte de la evidencia publicada, a pesar de mostrar efectos específicos sobre la pérdida de peso, IMC y reducción del porcentaje de grasa, no evaluó con precisión sus efectos sobre parámetros fisiológicos y bioquímicos, principalmente en los tejidos hepático, cardíaco y renal. Concluimos que las estrategias para controlar el sobrepeso y la obesidad no necesariamente tienen que imponer restricciones sobre nutrientes, especialmente los carbohidratos, o aumentar la ingesta de grupos de alimentos cuyo consumo excesivo se ha asociado con diferentes patologías.

Effect of a Ketogenic Diet on the Nutritional Parameters of Obese Patients: A Systematic Review and Meta-Analysis

“…Similar to balanced diets consisting mainly of bland fresh foods or meal replacement diet programs, it is important to highlight people’s low tolerance for KD due to the limited palatability of high lipid foods [ 44 ]; it is clearly not applicable as a long-term strategy. Moreover, the literature reports increases in uric acid, creatinine, and aspartate aminotransferase [ 8 , 45 ], as well as the short-term symptoms described in the results of this SR. Indeed, if the safety and effectiveness of following a KD cannot be assured [ 9 ], it must be recommended with extreme precaution.…”

دراسة تأثير النظام الغذائي الكيتوني على فقدان الوزن ودهون الدم في الفئران البدينة

“…Look into it. (Perticone et al 2019) A ketogenic diet has been shown to be quite successful for weight loss, particularly in reducing fat mass while maintaining fat-free mass.According to (Corrêa et al 2019), measures to control overweight and obesity do not necessarily need to impose restrictions on certain nutrients, particularly carbohydrates, or boost the intake of food categories whose excessive consumption has been linked to various diseases. (Goldberg et al 2021) Many patients can lose weight by following a low-carbohydrate diet.…”