OBJECTIVE: To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement among adults who are overweight or obese.
DESIGN: Systematic review and network meta-analysis of randomised trials.
DATA SOURCES: Medline, Embase, CINAHL, AMED, and CENTRAL from database inception until September 2018, reference lists of eligible trials, and related reviews.
STUDY SELECTION: Randomised trials that enrolled adults (≥18 years) who were overweight (body mass index 25-29) or obese (≥30) to a popular named diet or an alternative diet.
OUTCOMES AND MEASURES: Change in body weight, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, systolic blood pressure, diastolic blood pressure, and C reactive protein at the six and 12 month follow-up.
REVIEW METHODS: Two reviewers independently extracted data on study participants, interventions, and outcomes and assessed risk of bias, and the certainty of evidence using the GRADE (grading of recommendations, assessment, development, and evaluation) approach. A bayesian framework informed a series of random effects network meta-analyses to estimate the relative effectiveness of the diets.
RESULTS: 121 eligible trials with 21 942 patients were included and reported on 14 named diets and three control diets. Compared with usual diet, low carbohydrate and low fat diets had a similar effect at six months on weight loss (4.63 v 4.37 kg, both moderate certainty) and reduction in systolic blood pressure (5.14 mm Hg, moderate certainty v 5.05 mm Hg, low certainty) and diastolic blood pressure (3.21 v 2.85 mm Hg, both low certainty). Moderate macronutrient diets resulted in slightly less weight loss and blood pressure reductions. Low carbohydrate diets had less effect than low fat diets and moderate macronutrient diets on reduction in LDL cholesterol (1.01 mg/dL, low certainty v 7.08 mg/dL, moderate certainty v 5.22 mg/dL, moderate certainty, respectively) but an increase in HDL cholesterol (2.31 mg/dL, low certainty), whereas low fat (-1.88 mg/dL, moderate certainty) and moderate macronutrient (-0.89 mg/dL, moderate certainty) did not. Among popular named diets, those with the largest effect on weight reduction and blood pressure in comparison with usual diet were Atkins (weight 5.5 kg, systolic blood pressure 5.1 mm Hg, diastolic blood pressure 3.3 mm Hg), DASH (3.6 kg, 4.7 mm Hg, 2.9 mm Hg, respectively), and Zone (4.1 kg, 3.5 mm Hg, 2.3 mm Hg, respectively) at six months (all moderate certainty). No diets significantly improved levels of HDL cholesterol or C reactive protein at six months. Overall, weight loss diminished at 12 months among all macronutrient patterns and popular named diets, while the benefits for cardiovascular risk factors of all interventions, except the Mediterranean diet, essentially disappeared.
CONCLUSIONS: Moderate certainty evidence shows that most macronutrient diets, over six months, result in modest weight loss and substantial improvements in cardiovascular risk factors, particularly blood pressure. At 12 months the effects on weight reduction and improvements in cardiovascular risk factors largely disappear.
SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015027929.
ANTECEDENTES: Existe una necesidad para el desarrollo de las intervenciones más eficaces para lograr una alimentación saludable, mejorar el envejecimiento saludable, y para reducir el riesgo de enfermedades relacionadas con la edad. El objetivo de este estudio fue identificar las técnicas de cambio de comportamiento (BCT) utilizados en las intervenciones de cambio de comportamiento dietéticas complejas y explorar la asociación entre BCT utilizados y efectividad de la intervención.
MÉTODOS: Se realizó un análisis secundario de los datos de una revisión sistemática anterior con meta-análisis de la eficacia de las intervenciones dietéticas entre las personas en edad de jubilación. BCT se identificaron utilizando la taxonomía fiable CALO-RE en estudios que informan de frutas y verduras (F y V) Consumo como resultados. La diferencia media en la F y la ingesta de V entre los brazos de activos y control se comparó entre los estudios en los que se identificaron los BCT frente a aquellos que no utilizan las BCT. Se utilizaron modelos de efectos aleatorios meta-regresión para evaluar la asociación de intervenciones BCT con F y V tomas.
RESULTADOS: Veintiocho de los 40 BCT enumerados en la taxonomía CALO-RE se identificaron en los 22 artículos revisados. Los estudios que utilizan 'barrera de identificación / resolución de problemas' las técnicas (93 g, 95% de confianza (IC) del 48 a 137 F y una mayor ingesta V), "Plan de apoyo social / cambio social" (78 g; IC del 95%: 24-132 mayor F y la ingesta V), "la fijación de objetivos (resultados) '(55 g IC del 95% 7-103 mayor F y la ingesta V),' uso de seguimiento de avisos" (66 g; IC del 95%: 10-123 mayor F y el consumo de V) y "proporcionar retroalimentación sobre el desempeño '(39 g, IC del 95% -2-81 mayor F y la ingesta de V) se asociaron con mayores efectos de las intervenciones en F y el consumo de V en comparación con los estudios que no utilizan estos BCT. El número de BCT por estudio varió de 2 a 16 (mediana = 6). Meta-regresión mostró que uno BCT adicional condujo a 8,3 g (95% IC 0,006 a 16,6 g) aumento de la ingesta de F y V.
CONCLUSIONES: BCT general, este estudio ha identificado asociados con eficacia lo que sugiere que estos podrían ser los ingredientes activos de las intervenciones dietéticas que sean eficaces en el aumento de la ingesta de F y V en los adultos mayores. Para las intervenciones dirigidas a los del grupo de edad peri-jubilación, "la resolución de la barrera de identificación / problema" y "plan de apoyo social / cambio social 'pueden ser particularmente útiles para aumentar la efectividad de las intervenciones dietéticas.
To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement among adults who are overweight or obese.
DESIGN:
Systematic review and network meta-analysis of randomised trials.
DATA SOURCES:
Medline, Embase, CINAHL, AMED, and CENTRAL from database inception until September 2018, reference lists of eligible trials, and related reviews.
STUDY SELECTION:
Randomised trials that enrolled adults (≥18 years) who were overweight (body mass index 25-29) or obese (≥30) to a popular named diet or an alternative diet.
OUTCOMES AND MEASURES:
Change in body weight, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, systolic blood pressure, diastolic blood pressure, and C reactive protein at the six and 12 month follow-up.
REVIEW METHODS:
Two reviewers independently extracted data on study participants, interventions, and outcomes and assessed risk of bias, and the certainty of evidence using the GRADE (grading of recommendations, assessment, development, and evaluation) approach. A bayesian framework informed a series of random effects network meta-analyses to estimate the relative effectiveness of the diets.
RESULTS:
121 eligible trials with 21 942 patients were included and reported on 14 named diets and three control diets. Compared with usual diet, low carbohydrate and low fat diets had a similar effect at six months on weight loss (4.63 v 4.37 kg, both moderate certainty) and reduction in systolic blood pressure (5.14 mm Hg, moderate certainty v 5.05 mm Hg, low certainty) and diastolic blood pressure (3.21 v 2.85 mm Hg, both low certainty). Moderate macronutrient diets resulted in slightly less weight loss and blood pressure reductions. Low carbohydrate diets had less effect than low fat diets and moderate macronutrient diets on reduction in LDL cholesterol (1.01 mg/dL, low certainty v 7.08 mg/dL, moderate certainty v 5.22 mg/dL, moderate certainty, respectively) but an increase in HDL cholesterol (2.31 mg/dL, low certainty), whereas low fat (-1.88 mg/dL, moderate certainty) and moderate macronutrient (-0.89 mg/dL, moderate certainty) did not. Among popular named diets, those with the largest effect on weight reduction and blood pressure in comparison with usual diet were Atkins (weight 5.5 kg, systolic blood pressure 5.1 mm Hg, diastolic blood pressure 3.3 mm Hg), DASH (3.6 kg, 4.7 mm Hg, 2.9 mm Hg, respectively), and Zone (4.1 kg, 3.5 mm Hg, 2.3 mm Hg, respectively) at six months (all moderate certainty). No diets significantly improved levels of HDL cholesterol or C reactive protein at six months. Overall, weight loss diminished at 12 months among all macronutrient patterns and popular named diets, while the benefits for cardiovascular risk factors of all interventions, except the Mediterranean diet, essentially disappeared.
CONCLUSIONS:
Moderate certainty evidence shows that most macronutrient diets, over six months, result in modest weight loss and substantial improvements in cardiovascular risk factors, particularly blood pressure. At 12 months the effects on weight reduction and improvements in cardiovascular risk factors largely disappear.
