Consuming a whey protein drink before each meal reduces blood sugar spikes in people with type 2 diabetes, a new study reports. 

“Given the financial implications associated with anti-hyperglycaemic pharmacotherapies, the provision of premeal whey protein supplementation may offer an effective non-pharmaceutical approach to regulate glycaemia,” the authors wrote. 

The study, “Thrice daily consumption of a novel premeal shot containing a low dose of whey protein increases time in euglycemia during 7 days of free-living in individuals with type 2 diabetes,” was published in BMJ Open Diabetes Research & Care.

Very high blood glucose after meals raises glycated haemoglobin (HbA1c) levels and increases cardiovascular disease risk in people with type 2 diabetes. Therefore, preventing post-meal blood glucose spikes is crucial. 

Past studies show that eating protein-rich foods before meals increases the release of insulin and proteins that slow digestion, lowering blood glucose after meals. While these studies have shown a significant reduction in HbA1c (average blood glucose over two to three months), they don’t provide information about daily blood glucose changes.   

Now, researchers in the United Kingdom investigated the effect of consuming a protein drink before main meals on blood glucose in people with type 2 diabetes over seven days. 

All participants were fitted with a continuous glucose monitor to track their blood glucose levels before the study began. The researchers instructed the participants to eat their regular diets and continue taking their medication but consume either a whey protein or control drink ten minutes before their main meals for seven days. The participants drank the whey protein for one week and then the control drink the following week. 

The whey protein drink contained 15.6g of protein, 3g of carbohydrates and 2.3g of fat, while the control drink had 3.9g of carbohydrates, 2.2g of fat and less than 0.1g of protein. Participants’ blood glucose levels were monitored regularly over the seven days to determine how long their blood sugar levels remained within a target healthy range. 

In total, 18 Caucasian adults (13 males) completed the study. The average age of the cohort was 50 years, with a mean HbA1c of 57.4 mmol/mol (7.4%). The participants had lived with diabetes for an average of six years. 

Compared to the control drink, participants’ blood glucose levels were 0.6 mmol/mol lower after the protein drink. The frequency of post-meal high blood glucose was also reduced by 8.3% with the protein drink, reducing the amount of time they had high blood glucose by 117 mins. Consequently, the time they maintained blood glucose levels within target ranges increased by 8.7%.

“For the first time, we demonstrate that daily hyperglycaemia can be significantly reduced by the provision of a low dose of WP [whey protein] (15g) ingested prior to each main meal over 7 days of free-living. This enabled patients to achieve 2 hours more per day spent within euglycemia [normal blood glucose], without increasing the risk of hypoglycaemia. These results occurred without a change in patient medication, dietary intake, or physical activity levels, thereby demonstrating the utility of premeal WP supplementation for the management of hyperglycaemia,” the authors wrote. 

The researchers believe that whey protein works by slowing digestion and stimulating proteins that increase insulin sensitivity and regulate blood glucose. 

“We believe the whey protein works in two ways, first, by slowing down how quickly food passes through the digestive system and secondly, by stimulating a number of important hormones that prevent the blood sugars climbing so high,” Daniel West, senior lecturer and principal investigator working in the Human Nutrition Research Centre and Diabetes Research Group at Newcastle University said in a press release.

Unlike previous studies conducted under strict research conditions, this one has been done in real-life settings, meaning that the results may apply to the public.  

“While previous studies for a few hours in the lab have shown the potential for this dietary intervention, this is the first time that people have been monitored as they go about normal life,” West said.

“People were able to stick to the regime and liked the idea of having a convenient, tasty, small pre-made drink that could be carried with them and taken before meals,” Kieran Smith, lead author and PhD student at Newcastle University said. 

The scientists suggest further studies to determine if whey protein’s glucose-lowering effect is sustainable long-term and clinically relevant. They plan to investigate if plant proteins, such as peas, mushrooms and potatoes, also have similar blood glucose-lowering properties. 

“As we see growing numbers of people around the world developing diabetes, investigating the potential of alternatives to drugs such as food supplements becomes important,” Dr West said. 

The Key Message

Food sequencing is an evidence-based strategy for blood glucose control. Recent studies show that eating protein, fat or fibre-rich foods before carbohydrates significantly reduces post-meal blood sugar and HbA1c levels. 

This study adds to those findings by showing that consuming small amounts of proteins before meals keeps blood sugar in healthy ranges for up to two hours longer daily without increasing the risk of hypoglycaemia. 

You don’t need to buy a whey protein powder to achieve similar glucose-lowering effects. You can accomplish this by eating protein-rich foods, such as tofu, chicken, beef or fish and vegetables before eating starchy carbs like potatoes and rice.