Ayuno intermitente: impacto en el descenso de peso y la salud cardiometabólica / Intermittent fasting: impact in weight lost and cardiometabolic health

Resumen Introducción: la obesidad representa una importante problemática a nivel mundial, esto genera la necesidad de encontrar nuevas estrategias terapéuticas que contribuyan a tratar dicha enfermedad. En los últimos años, ha surgido el ayuno intermitente (AI) como una posible alternativa dietoterápica en el descenso de peso y en la mejora de variables cardiometabólicas, aunque la evidencia científica es controvertida. Objetivos: evaluar la evidencia científica disponible respecto a la efectividad del ayuno intermitente en el descenso de peso y en la mejora de las variables cardiometabólicas en comparación con la restricción energética continua. Materiales y Método: se ha llevado a cabo una búsqueda sistemática de ensayos clínicos aleatorizados (ECA) en las bases de datos PUBMED y Cochrane Library. Se incluyeron 11 ECA, que compararan AI con restricción energética continua (REC) con un rango de duración de 4 a 48 semanas, en mujeres y hombres con un índice de masa corporal (IMC) ≥25 kg/m2 y que hayan evaluado descenso de peso y variables cardiometabólicas. Resultados: el AI presentó una mediana de descenso de peso de 5,5 kg (RIQ: 4,7;6,86 kg), mientras que para la REC fue de 4,8 kg (RIQ: 3,8;6,6 kg). El IMC, la masa grasa, la masa libre de grasa y circunferencia de cintura, se redujeron de manera significativa tanto para la intervención como para el comparador. Asimismo, las variables cardiometabólicas presentaron mejoras respecto a los valores iniciales, sin embargo, evidenciaron resultados heterogéneos. Conclusiones: tanto el AI como la REC resultaron ser efectivas para la mejora de las variables estudiadas. La intervención no demostró ser mejor que el comparador.

Abstract Introduction: obesity represents a major problem worldwide, and this generates the need to find new therapeutic tools that contribute to the treatment of this disease. In recent years, intermittent fasting (IF) has emerged as a possible dietary alternative in weight loss and improvement of cardiometabolic variables, although the scientific evidence is controversial. Objectives: to evaluate the available scientific evidence regarding the effectiveness of intermittent fasting in weight loss and in the improvement of cardiometabolic variables in comparison with continuous energy restriction. Materials and Method: a systematic search of PUBMED and Cochrane Library databases for randomized clinical trials (RCTs) has been conducted. Eleven RCTs were included, comparing IF with continuous energy restriction (CER) with a duration range of 4 to 48 weeks, in women and men with a body mass index (BMI) ≥25 kg/m2 and who assessed weight loss and cardio metabolic variables. Results: the IF presented a median weight loss of 5.5 kg (IQR:4.7; 6.86 kg), while for CER it was 4.8 kg (IQR: 3.8; 6.6 kg). BMI, fat mass, fat-free mass, and waist circumference were significantly reduced for both the intervention and the comparator. Likewise, the cardiometabolic variables presented improvements with respect to the initial values, however, they showed heterogeneous results. Conclusions: both IF and CER proved to be effective in improving the variables studied; the intervention did not prove to be better than the comparator.

Dietary Interventions for Weight Loss

@#Obesity is a complex and chronic condition that requires continuing care. A variety of diet plans are available for use in the clinical setting. Exactly what type of diet may be most beneficial remains controversial. Numerous clinical trials have been carried out over the years comparing an array of dietary interventions for weight loss, including calorie restriction diets, altered macronutrient composition diets or specific dietary patterns. This paper will provide an overview of the evidence-based dietary interventions for clinical practice.

Moderate intensity swimming training on bone mineral density preservation under food restriction in female rats

Abstract Aim: To investigate the effect of moderate-intensity swimming training on bone mineral density under a 20% food restriction (FR) schedule for 12 weeks in female rats. Methods: Forty female Wistar rats were distributed into four groups: control (CG), exercised (EG), food restriction (FRG), and food restriction/exercised (FREG). At 95 days. the animals were subjected to aquatic adaptation and then performed the critical load test to individually determine the critical load intensity (CLi, % of body mass). Exercised groups swam 5 days a week, 30 minutes daily with weekly adjustment of the load equivalent to 80% of the CLi. The FR schedule was 20% in relation to CG and started concomitantly with physical training (PT). After 12 weeks, visceral fat weight was recorded and the femur was collected for biophysical and biomechanical analysis. Results: FR and exercise training promoted visceral fat reduction (p<0.01). FR reduced bone mineral density (p<0.01), while exercise training prevented such reduction. On the other hand, FR and exercise training did not promote significant changes in biomechanical parameters of the femur. Conclusion: Exercise training at moderate intensity was efficient in preserving bone mineral density despite long term of FR at 20%.

Energy restriction and impact on indirect calorimetry and oxidative stress in cardiac tissue in rat.

Caloric restriction, defined as a reduction in calorie intake below ad libitum, without malnutrition can have beneficial effects. In this study, we evaluated the impact of caloric restriction of 30 and 60% on calorimetric parameters and oxidative stress in cardiac tissue in rats. Rats were randomly divided into 3 groups (n = 8): G1 = control; G2 = rats exposed to dietary restriction of 30%; and G3 = rats exposed to dietary restriction of 60%. Energy restriction decreased final body weight, oxidation of carbohydrates and lipid, oxygen consumption (VO2), carbon dioxide production (VCO2), resting metabolic rate (RMR), but elevated respiratory quotient (RQ). G3 animals also displayed an imbalance in the oxidant/antioxidant system, as revealed by the decrease in the lipid hydroperoxide (LH) level and GSH-Px activity in heart tissue. In conclusion, dietary restriction decreased oxidative metabolism, as seen by the colorimetric profiles and controlled oxidative stress in cardiac tissue.

Comparing the impact of chronic energy restriction and vitamin E supplementation on the behavior of adult rats / Comparación del impacto entre la restricción energética crónica y la suplementación con vitamina E en el comportamiento de ratas adultas

The purpose of this work was to investigate the influence of energy restriction and vitamin E supplementation on memory, learning, anxiety and spontaneous locomotion in adult rats. Three-month old male Wistar rats were grouped according to diet: Control (AIN 93-M; n=18), Supplemented (AIN 93-M + 1425 IU all-rac-alph-tocopheryl acetate/kg diet; n=22) and Restricted (AIN 93-M with 30 percent reduction in carbohydrate energy; n=23). Sixteen weeks after, the passive avoidance (PA), elevated plus-maze (EPM) and open field (OF) tests were applied. In the EPM test, the behavioral profile of the supplemented group was characterized by a lower frequency of entries into the open arms (P < 0,026), whereas the restricted group showed a lower frequency of head dipping (P < 0,003). The ratio between the time span of the shocks and the number of attempts were larger for the supplemented than for the non-supplemented animals (P = 0,0474), thus suggesting a delay in learning in the PA test. Taken together, these results suggest that a long-term combination of carbohydrate energy restriction in rats should not cause negative behavioral alterations. Compared with vitamin E supplementation, the restricted diet performed equally or better in rats as an alternate antioxidant diet.

Se investigó la influencia de la restricción energética en comparación a la suplementación con vitamina E en la memoria, aprendizaje, ansiedad y locomoción espontánea en ratas adultas. Machos Wistar de tres meses de edad fueron agrupados de acuerdo a las dietas: Control (AIN 93-M, n=18), Suplementados (AIN 93-M + 1425 UI all-rac-alfa-tocoferil acetato /kg de dieta; n=22) y Restrictos (AIN 93-M con 30 por ciento de restricción energética en los carbohidratos; n=23). Dieciséis semanas después, fueron aplicadas las pruebas de esquiva pasiva (PA), laberinto elevado en cruz (EPM) y de campo abierto (OF). En la prueba de EPM, el grupo suplementado mostró una menor frecuencia de entradas en los corredores abiertos (P < 0,026), mientras el grupo restricto registró menor frecuencia de bajadas de cabeza (P = 0,003). La razón entre la duración de los choques y el número de intentos fue superior para el grupo suplementado, que para los no suplementados (P = 0,0474), lo cual sugiere un leve perjuicio en el aprendizaje de los suplementados, según la prueba de PA. Tomados en conjunto, estos resultados sugieren que la restricción crónica en energía de carbohidratos no provoca alteraciones negativas en el comportamiento de ratas adultas y que sus beneficios pueden superar los obtenidos al suplementar la dieta patrón con vitamina E, como opción de dieta antioxidante.

The Effect of an Energy Restriction Program on the Weight Loss and the Change of Biochemical nutritional Status in Obese Women / 대한지역사회영양학회지

This study was conducted to investigate the effect of an energy restriction program on the weight loss and changes of the biochemical nutritional status for 35 obese women. The energy restriction program took place over a 3-week period that was devided into two parts. The first part consisted of 750-800kcal diet and the second part of 800-1000kcal. Subjects were provided a low energy formula and a menu for the recommended diet. Anthropometric and biochemical measurement before and after the energy restriction program were estimated. Mean weight loss was 3.0 kg, accordingly the obestiy rate was lowered from 40.2 to 34.4, BMI from 29.2 to 28.9 and fat weight from 23.3 kg to 21.0 kg(<0.01.<0.05). Waist circumference loss was most prominent(4.4%) compared to triceps(21% loss)and hip circumference(2.2%loss). Mean RBC count, hemoglobin and hematocrit were significantly lowered(<0.01) but they were in the normal range. Systolic blood pressure was significantly decreased from 124.1 mmHg to 113.1 mmHg . Mean SGOT and SGPT were lowered from 29.3u/L to 20.0u/L and from 28.7u/L to 16.6u/L, respectively. It seems that the 3 weeks of energy restriction program used in this study was effective in improving anthropometric measurements without producing deficiency of iron or other susceptible nutrients.

Effect of Insulin Like Growth Factor / 대한내분비학회지

recombinant human IGF-I in energy-restriction model. Experimental design; Sprague-Dawley rats(n=20) weighing 90-100g were used. Rats were fed a control diet two times a day(AM 8-11, PM 5-8) for four days after arrival and then assigned to one of three groups: control, energy-restricted, energy-restricted IGF-I treatment group. Energy restricted group was given with a decrese of 25% in the energy without changes in the protein by feeding 88% by weight to energy-restricted diet. During the 10days of energy restriction, the growth rate was reduced by 35%(2.70+-0.18g/day in energy restricted group vs. 4.13+-0.75g/day in the control group). At sacrifice, the tail lengh and weight of organs were not significantly decreased except the spleen and thymus(-17%: P<0.05). Serum IGF-I was reduced by 19% at the end of 10days of energy restriction. The glycemia, measured each day by glucometer from blood collected at the tail, was not reduced by energy restriction(105.4+-7.7 in control group vs. 101.3+-4.1mg/dl). The abundance of serum IGF-BPs was unchanged by this restriction.Despite the 1.5 fold increase of IGF-I concentration in energy restricted IGF-I injection group at sacrifice(1994+-172ng/ml vs. 1221+-110 ng/ml energy restricted group), IGF-I treatment(300 ug/day in twice sc injection for 6day) did not significantly accelerate the growth rate(body weight)(2.87+-0.20 vs. 2.70+-0.18g/day in energy restricted group).The glycemia was slightly reduced by IGF-I treatment(91.7+-5.0 mg/dl vs. 101.3+-4.5 mg/dl in energy restricted group), but it was not significant. However, the spleen and thymus weight, decreased by energy restriction, was completely normalized by IGF-I treatment.In summary, lack of a significant anabolic response to injection of IGF-I during energy restriction in this study may be associated with the compensatory growth response(alterations in dietary protein utilization) which followed initial period of energy restriction.

INFLUENCE OF DIETARY ENERGY RESTRICTION ON THE GROWTH, DEVELOPMENT AND ENDURANCE IN CHINESE KUNMING MICE / 营养学报

0.2); whereas that in group Ⅲ 1.24 ?0.38g, significantly different (P0.05),the dietary energy re-striction did not affect the producing and scavenging of free radical in theorgans.