Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes.

OBJECTIVE: Nutrition therapy is an integral part of self-management education in patients with type 2 diabetes. Carbohydrates with a low glycemic index are recommended, but the ideal amount of carbohydrate in the diet is unclear. We performed a meta-analysis comparing diets containing low to moderate amounts of carbohydrate (LCD) (energy percentage below 45%) to diets containing high amounts of carbohydrate (HCD) in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: We systematically reviewed Cochrane library databases, EMBASE, and MEDLINE in the period 2004-2014 for guidelines, meta-analyses, and randomized trials assessing the outcomes HbA1c, BMI, weight, LDL cholesterol, quality of life (QoL), and attrition. RESULTS: We identified 10 randomized trials comprising 1376 participants in total. In the first year of intervention, LCD was followed by a 0.34% lower HbA1c (3.7 mmol/mol) compared with HCD (95% CI 0.06 (0.7 mmol/mol), 0.63 (6.9 mmol/mol)). The greater the carbohydrate restriction, the greater the glucose-lowering effect (R=-0.85, p<0.01). At 1 year or later, however, HbA1c was similar in the 2 diet groups. The effect of the 2 types of diet on BMI/body weight, LDL cholesterol, QoL, and attrition rate was similar throughout interventions. LIMITATIONS: Glucose-lowering medication, the nutrition therapy, the amount of carbohydrate in the diet, glycemic index, fat and protein intake, baseline HbA1c, and adherence to the prescribed diets could all have affected the outcomes. CONCLUSIONS: Low to moderate carbohydrate diets have greater effect on glycemic control in type 2 diabetes compared with high-carbohydrate diets in the first year of intervention. The greater the carbohydrate restriction, the greater glucose lowering, a relationship that has not been demonstrated earlier. Apart from this lowering of HbA1c over the short term, there is no superiority of low-carbohydrate diets in terms of glycemic control, weight, or LDL cholesterol.

Early enteral nutrition within 24 h of intestinal surgery versus later commencement of feeding: a systematic review and meta-analysis.

BACKGROUND: We set out to evaluate early commencement of post-operative enteral nutrition versus traditional management in patients undergoing gastrointestinal surgery. METHODS: Electronic databases were searched, references lists were scanned and authors contacted for additional information. We looked for randomised controlled trials comparing early commencement of feeding (within 24 h) with no feeding in patients undergoing gastrointestinal surgery. Primary endpoints were wound infections, intra-abdominal abscesses, pneumonia, anastomotic leakage, mortality, length of hospital stay and complications of feeding. Data were combined to estimate the common relative risk of post-operative complications and associated 95% confidence intervals. RESULTS: Thirteen trials, with a total of 1,173 patients, fulfilled our inclusion criteria. Mortality was reduced with early post-operative feeding. Early post-operative feeding increased vomiting. The direction of effect is suggestive of a reduction of risk of post-surgical complications and reduced length of hospital stay. CONCLUSION: There is no obvious advantage in keeping patients 'nil by mouth' following gastrointestinal surgery. Early enteral nutrition is associated with reduced mortality, though the mechanism is not clear. This review supports the notion that early commencement of enteral feeding may be of benefit.