Postprandial Glycemic and Insulinemic Responses to Common Breakfast Beverages Consumed With a Standard Meal in Overweight and Obese Individuals
Authors: Li Jia , Janle Elsa , Campbell Wayne W 
Published: November 2023

Objective

The purpose of this study was to assess the postprandial glycemic and insulinemic responses to isovolumetric and isocarbohydrate quantities of sugar sweetened coffee, reduced calorie orange juice (OJ), low‐fat milk (1% fat), and water control consumed with a standard breakfast sandwich.

Methods

Forty‐six overweight and obese adults were recruited and categorized with normal glucose tolerance or prediabetes using HbA1c<5.7 and 5.7≤HbA1c<6.5%, respectively. Twenty‐nine (20F/9M) individuals had normal glucose tolerance (BMI: 32.3±0.8kg/m2, Age: 50±2y, Mean±SE) and 17 (13F/4M) had prediabetes (BMI: 33±1.2kg/m2, Age: 49±3y). Each subject was provided with standardized meals to consume the day before each testing day. On 4 mornings separated by at least one week, each subject consumed a standard breakfast sandwich with one of the 4 beverages (240mL) in random order. The test beverages (except water) each contained 12g digestible carbohydrate, and the digestible carbohydrate in the sandwich plus water, coffee, OJ, and milk were 63, 75, 75, and 75g, respectively. Plasma glucose and insulin concentrations were measured from aliquots obtained before (fasting blood) and at 30‐minute intervals for 4 hours after consuming the meals. Incremental areas under the curve (AUC) were computed for glucose and insulin.

Results

Glucose AUC(0–4h) was highest in coffee compared to OJ, water, and milk (water: 2903±274a, coffee: 3425±275b, OJ:2741±275a, milk: 2752±274a mg/dL•min, abc: values with different letters were significantly different, p<0.05). This difference in glucose responses among the beverages was also significant for the glucose AUC(0–2h), but not the glucose AUC(2–4h).

Insulin AUC(0–4h) was higher for coffee and milk vs. OJ and water (water: 7515±772a, coffee: 9406±774b, OJ: 7635±773a; milk: 9068±775b μU/mL•min, p<0.05). During the first 2 hours after meal consumption, coffee and milk had higher insulin AUC(0–2h) than OJ and water, while coffee had higher insulin AUC(0–2h) than milk (water: 6312±599a, coffee: 8217±601c, OJ: 6201±599a, and milk: 7109±601b μU/mL•min, p<0.05). During the 2–4 hour period, milk had the highest insulin AUC(2–4h) (water: 1203±236a, coffee: 1188±236a, OJ: 1433±236a, milk: 1959±236b μU/mL•min, p<0.05).

When the glucose and insulin responses were adjusted for the carbohydrate content (by dividing the AUC by the digestible carbohydrate quantity for each test sandwich plus beverage), meals consumed with coffee and water had higher glucose AUC(0–4h) than OJ and milk (water: 46.1±3.8a, coffee: 45.7±3.8a, OJ: 36.5±3.8b, milk: 36.7±3.8b mg/dL•min per gram carbohydrate, p<0.05). Insulin AUC(0–4h) was lower in OJ than the other beverages (water: 119±10.6a, coffee: 126±10.6a, OJ: 102±10.6b, milk: 121±10.6a μU/mL•min per gram carbohydrate, p<0.05).

Conclusion

For middle‐aged overweight and obese adults, common breakfast beverages containing the same amount of digestible carbohydrate elicit different postprandial glycemic and insulinemic responses. Sugar sweetened coffee had a higher glycemic responses than low‐fat milk and reduced calorie orange juice, which were not different than water.

Support or Funding Information

National Dairy Council, NIH #UL1TR001108