Effect of a low dose whey/guar preload on glycemic control in people with type 2 diabetes-a randomised controlled trial

Abstract

ObjectiveLarge preloads of protein and fat have been shown to lower glucose after a carbohydrate-rich meal in people with type 2 diabetes but add a considerable energy burden. Low calorie preloads [<5% of daily energy intake] have been tested in this study in people with prediabetes and with type 2 diabetes.Research design and methodsThis was an unblinded randomised crossover study with two placebo days and two active treatment days. Glucose was measured for 3 hours with fingerprick samples as well as continuous glucose monitoring [CGMS]. Twenty-four subjects with pre-diabetes or moderately controlled type 2 diabetes [fasting glucose < 10 and HbA1c < 8.5%] were recruited. The preload contained 17 g whey protein plus 3 g lactose and 5 g guar, and 1 g flavour material [including sucralose] dissolved in 150 ml cold water or 150 ml cold water with no additives. The breakfast test meal consisted of 2 slices of bread, margarine and jam [3 slices for men] with the test drink 15 minutes beforehand.ResultsPeak fingerprick glucose was reduced by 2.1 mmol/L at 45 min [p < 0.0001]. Average fingerprick glucose over 3 hours was reduced by 0.8 mmol/L [p = 0.0003]. There was no difference between those with diabetes or prediabetes or those on medication or not on medication.ConclusionsAn 80 kcal whey protein/fibre preload can lower average glucose over 3 hours by 0.8 mmol/L. If used long term before at least two carbohydrate-rich meals/day this preload could lower HbA1c by up to 1%.Trial registrationThe trial was registered with the Australian New Zealand Clinical Trials Registry number ACTRN12612001251819.

A whey/guar “preload” improves postprandial glycaemia and glycated haemoglobin levels in type 2 diabetes: A 12‐week, single‐blind, randomized, placebo‐controlled trial

“…Gastric emptying is a major determinant of postprandial glycaemia, accounting for ~35% of the variance in glucose excursions after ingestion of oral glucose in both healthy people and those with T2DM, consistent with the findings in the present study. Both whey protein and guar gum are associated with slowing of gastric emptying, and a low‐dose combination of these had previously been shown to reduce postprandial glycaemia acutely . In the present study, the same combination of whey/guar preload was associated with slowing of gastric emptying, and this effect was sustained at the end of 12 weeks of treatment.…”

“…Data are mean values ± SEM emptying, 18 and a low-dose combination of these had previously been shown to reduce postprandial glycaemia acutely. 17 In the present study, the same combination of whey/guar preload was associated with slowing of gastric emptying, and this effect was sustained at the end of 12 weeks of treatment. Moreover, there was a strong relationship between the magnitude of the postprandial increment in blood glucose and the rate of gastric emptying, consistent with the concept that slowing of gastric emptying is key to the reduction in postprandial glycaemia.…”

“…The slowing of gastric emptying and reduction in glycaemia were less marked when the same load of whey was ingested with the meal, establishing that the timing of protein ingestion in relation to the meal may be important. Similar acute findings have been reported when a preload incorporating low‐dose whey (17 g) together with guar (5 g) was given to people with T2DM or prediabetes . Guar, a viscous polysaccharide, can itself reduce postprandial glycaemic excursions by slowing both gastric emptying and glucose absorption in the small intestine…”

“…Similar acute findings have been reported when a preload incorporating low-dose whey (17 g) together with guar (5 g) was given to people with T2DM or prediabetes. 17 Guar, a viscous polysaccharide, can itself reduce postprandial glycaemic excursions by slowing both gastric emptying and glucose absorption in the small intestine. 18 The aims of the present study were to determine the effects of a twice-daily low-dose whey/guar preload taken 15 minutes before breakfast and dinner over 12 weeks, in people with T2DM and relatively good glycaemic control treated with diet or metformin alone.…”

Postprandial Glycaemic, Hormonal and Satiety Responses to Rice and Kiwifruit Preloads in Chinese Adults: A Randomised Controlled Crossover Trial

“…Drugs have been developed to target postprandial glycaemia, and there are dietary strategies that have been tested, including adding protein and fat to carbohydrate, limiting carbohydrate intake, and reducing the carbohydrate load by making food choices based on the glycaemic index. Suppression of peak glucose has been reported previously with protein preloads [ 6 , 35 ]. The mechanism by which a protein preload has a moderating effect on glycaemia is by stimulating a greater insulin response [ 6 ].…”