Non-alcoholic fatty liver disease and the metabolic syndrome:Effects of weight loss and a review of popular diets,Are low carbohydrate diets the answer?

Non-alcoholic fatty liver disease （NAFLD） encompasses a wide spectrum of fat-induced liver injury, ranging from relatively benign steatosis to cirrhosis and liver failure. The presence of obesity and insulin resistance is strongly associated with non-alcoholic fatty liver and confers on it a greater risk of histologically advanced disease. There is a growing concern in the medical profession as the prevalence of this disease continues to rise in parallel with the rise in obesity and the metabolic syndrome. Treatment options are limited and dietary weight loss is often advised. Low fat diets are difficult to adhere to and recent studies have shown the potential of low carbohydrate diets for weight loss and improving insulin resistance. Thus far, no study has evaluated the effect of low carbohydrate diets on NAFLD. Future studies will be required to address this question and others with regards to the nutritional adequacy and long-term side effects of these diets.

The role of visceral adipose tissue on improvement in insulin sensitivity following Roux-en-Y gastric bypass:a study in Chinese diabetic patients with mild and central obesity

Background:Most Chinese patients with type 2 diabetes mellitus(T2DM)have mild obesity and central obesity.Central obesity is combined with insulin resistance.The aim of this study was to assess the effect of abdominal adipose tissue on insulin-sensitivity improvement after Roux-en-Y gastric bypass(RYGB)in Chinese diabetic patients with mild and central obesity.Methods:Seventeen T2DM patients with a mean body mass index of 30.3 kg/m^(2) were scheduled for laparoscopic RYGB.A hyperinsulinemic-euglycemic clamp and dual-energy X-ray absorptiometry were performed prior to surgery and 3 months after RYGB.The primary end points were the correlations between insulin sensitivity and abdominal adipose tissue,including visceral adipose tissue(VAT)and subcutaneous adipose tissue(SAT),before and 3 months after RYGB.Results:Indices of peripheral insulin sensitivity,including glucose-disposal rate(M value)and glucose infusion rate,were significantly increased after RYGB.Body-fat mass,VAT and SAT were significantly reduced after RYGB.The pre-operative M value was significantly correlated with VAT mass(r=–0.57,P=0.02),but not correlated with SAT mass.M value changes after RYGB were highly correlated with changes in VAT mass(r=–0.59,P=0.01),percentage of VAT mass(r=–0.66,P<0.01),VAT area(r=–0.56,P=0.02)and percentage of VAT area(r=–0.57,P=0.02).Conclusions:A significant correlation was observed between increased peripheral insulin sensitivity and decreased VAT following RYGB in Chinese patients with mild and central obesity.VAT and SAT were significantly decreased with improved insulin sensitivity after RYGB.VAT mass may be considered as an indication for gastric bypass during patient selection.