10 November 2015
A small study has suggested that the order in which a meal is eaten can affect blood glucose levels. It also suggests that people may benefit from timing their consumption of carbohydrates during a meal instead of simply avoiding certain foods.
The study was undertaken in 11 people with Type 2 diabetes on metformin who were overweight or obese. All participanrs fasted for 12 hours overnight before consuming a 628 calorie meal with protein, carbohydrates and fat. For one week, they consumed the carbohydrates (ciabatta bread and orange juice) first. Then they ate skinless grilled chicken, a small salad and buttered steamed broccoli 15 minutes later. The following week the order of the foods was reversed, finishing with the carbohydrates.
When the participants ate vegetables and proteins first, their blood glucose levels were about 29 per cent lower 30 minutes after starting the meal compared to when they ate the carbohydrates first. At 60 and 120 minutes after participants began eating, blood glucose levels were 37 per cent and 17 per cent lower, respectively, in comparison to when the carbohydrates were eaten first.
The reasons for this are not clear from this study but the researchers believe that the absorption of the carbohydrates is somehow slowed down by eating vegetables, which are low on the glycaemic index, perhaps because this delays how fast the carbohydrates get absorbed.
More research is needed to see if the results have a longer term impact on blood glucose than for the 2 hours after a meal.