None of the interventions were significantly better than the others in lowering glucose parameters .
The Mediterranean diet reduced HbA1c significantly compared to usual care but not compared to the Palaeolithic diet .
The effect of alterations in dietary practice irrespective of weight loss on glycaemic control can not be concluded from the present review .
BACKGROUND Overweight or obese individuals with type 2 diabetes are encouraged to lose weight for optimal glucose management , yet many find this difficult .
Determining whether alterations in dietary patterns irrespective of weight loss can aid glucose control has not been fully investigated .
METHODS We conducted a systematic review and meta- analysis aim ing to determine the effects of a Mediterranean diet compared to other dietary interventions on glycaemic control irrespective of weight loss .
Effects of supplemented isoenergetic diets differing in cereal fiber and protein content on insulin sensitivity in overweight humans.
BACKGROUND Despite their beneficial effects on weight loss and blood lipids , high-protein ( HP ) diets have been shown to increase insulin resistance and diabetes risk , whereas high-cereal-fiber ( HCF ) diets have shown the opposite effects on these outcomes . OBJECTIVE We compared the effects of isoenergetic HP and HCF diets and a diet with moderate increases in both cereal fibers and dietary protein ( Mix diet ) on insulin sensitivity , as measured by using euglycemic-hyperinsulinemic clamps with infusion of [6,6-(2)H(2)]glucose . DESIGN We r and omly assigned 111 overweight adults with features of the metabolic syndrome to 1 of 4 two-phased , 18-wk isoenergetic diets by group-matching . Per 3-d food protocol s , the percentages of energy derived from protein and carbohydrates and the intake of cereal fiber per day , respectively , were as follows-after 6 wk : 17 % , 52 % , and 14 g ( control ) ; 17 % , 52 % , and 43 g ( HCF ) ; 28 % , 43 % , and 13 g ( HP ) ; 23 % , 44 % , and 26 g ( Mix ) ; after 18 wk : 17 % , 51 % , and 15 g ( control ) ; 17 % , 51 % , and 41 g ( HCF ) ; 26 % , 45 % , and 14 g ( HP ) ; and 22 % , 46 % , and 26 g ( Mix ) . Eighty-four participants completed the study successfully and were included in the final analyses . Adherence was supported by the provision of tailored dietary supplements twice daily in all groups . RESULTS Insulin sensitivity expressed as an M value was 25 % higher after 6 wk of the HCF diet than after 6 wk of the HP diet ( subgroup analysis : 4.61 ± 0.38 compared with 3.71 ± 0.36 mg · kg(-1 ) · min(-1 ) , P = 0.008 ; treatment × time interaction : P = 0.005 ) . Effects were attenuated after 18 wk ( treatment × time interaction : P = 0.054 ) , which was likely explained by lower adherence to the HP diet . HP intake was associated with a tendency to increased protein expression in adipose tissue of the translation initiation factor serine-kinase-6 - 1 , which is known to mediate amino acid-induced insulin resistance . Biomarkers of protein intake indicated interference of cereal fibers with dietary protein absorption . CONCLUSION Greater changes in insulin sensitivity after intake of an isoenergetic HCF than after intake of an HP diet might help to explain the diverse effects of these diets on diabetes risk . This trial is registered at clinical trials.gov as NCT00579657
None of the interventions were significantly better than the others in lowering glucose parameters .
The Mediterranean diet reduced HbA1c significantly compared to usual care but not compared to the Palaeolithic diet .
The effect of alterations in dietary practice irrespective of weight loss on glycaemic control can not be concluded from the present review .
BACKGROUND Overweight or obese individuals with type 2 diabetes are encouraged to lose weight for optimal glucose management , yet many find this difficult .
Determining whether alterations in dietary patterns irrespective of weight loss can aid glucose control has not been fully investigated .
METHODS We conducted a systematic review and meta- analysis aim ing to determine the effects of a Mediterranean diet compared to other dietary interventions on glycaemic control irrespective of weight loss .