There was interaction by food source , with specific food sources showing beneficial effects ( fruit and fruit juice ) or harmful effects ( sweetened milk and mixed sources ) in substitution studies and harmful effects ( sugars‐sweetened beverages and fruit juice ) in addition studies on at least one outcome .
Conclusions Energy control and food source appear to mediate the effect of fructose‐containing sugars on glycaemic control .
Although most food sources of these sugars ( especially fruit ) do not have a harmful effect in energy matched substitutions with other macronutrients , several food sources of fructose‐containing sugars ( especially sugars‐sweetened beverages ) adding excess energy to diets have harmful effects .
Objective To assess the effect of different food sources of fructose‐containing sugars  on glycaemic control at different levels of energy control .
Incretin, insulinotropic and glucose-lowering effects of whey protein pre-load in type 2 diabetes: a randomised clinical trial
Abstract Aims /hypothesisSince protein ingestion is known to stimulate the secretion of glucagon-like peptide-1 ( GLP-1 ) , we hypothesised that enhancing GLP-1 secretion to harness its insulinotropic/beta cell-stimulating activity with whey protein pre-load may have beneficial glucose-lowering effects in type 2 diabetes . Methods In a r and omised , open-label crossover clinical trial , we studied 15 individuals with well-controlled type 2 diabetes who were not taking any medications except for sulfonylurea or metformin . These participants consumed , on two separate days , 50 g whey in 250 ml water or placebo ( 250 ml water ) followed by a st and ardised high-glycaemic-index breakfast in a hospital setting . Participants were r and omised using a coin flip . The primary endpoints of the study were plasma concentrations of glucose , intact GLP-1 and insulin during the 30 min following meal ingestion . Results In each group , 15 patients were analysed . The results showed that over the whole 180 min post-meal period , glucose levels were reduced by 28 % after whey pre-load with a uniform reduction during both early and late phases . Insulin and C-peptide responses were both significantly higher ( by 105 % and 43 % , respectively ) with whey pre-load . Notably , the early insulin response was 96 % higher after whey . Similarly , both total GLP-1 ( tGLP-1 ) and intact GLP-1 ( iGLP-1 ) levels were significantly higher ( by 141 % and 298 % , respectively ) with whey pre-load . Dipeptidyl peptidase 4 plasma activity did not display any significant difference after breakfast between the groups . Conclusions /interpretationIn summary , consumption of whey protein shortly before a high-glycaemic-index breakfast increased the early pr and ial and late insulin secretion , augmented tGLP-1 and iGLP-1 responses and reduced postpr and ial glycaemia in type 2 diabetic patients . Whey protein may therefore represent a novel approach for enhancing glucose-lowering strategies in type 2 diabetes . Trial registration Clinical Trials.gov NCT01571622 Funding The Israeli Ministry of Health and Milk Council funded the research
There was interaction by food source , with specific food sources showing beneficial effects ( fruit and fruit juice ) or harmful effects ( sweetened milk and mixed sources ) in substitution studies and harmful effects ( sugars‐sweetened beverages and fruit juice ) in addition studies on at least one outcome .
Conclusions Energy control and food source appear to mediate the effect of fructose‐containing sugars on glycaemic control .
Although most food sources of these sugars ( especially fruit ) do not have a harmful effect in energy matched substitutions with other macronutrients , several food sources of fructose‐containing sugars ( especially sugars‐sweetened beverages ) adding excess energy to diets have harmful effects .
Objective To assess the effect of different food sources of fructose‐containing sugars  on glycaemic control at different levels of energy control .