Report Title

The Effect of the Addition of Four Different Protein Isolates to A Fruit-Based Smoothie On Postprandial Blood Glucose in a Healthy Population

Collective Title

Master of Science in Nutrition and Dietetics Research Reports 2017


PURPOSE. The aim of this study was to investigate the effect of the addition of whey, soy, milk, or pea protein to fruit-based smoothies on postprandial blood glucose levels. METHOD. Eight subjects (1 male, 7 female, age 22.6 ±1.6 years, BMI 23.3 ± 2.5 kg/m2) participated in a randomized controlled study. Subjects consumed a 625 mL (2.5 cups) smoothie that contained 30 grams of either whey, soy, milk, or pea protein. A smoothie with no added protein was used as a control. All subjects were given the same type of smoothie on each test day. Finger sticks were used to measure blood glucose levels at baseline, 50 minutes, and 120 minutes after consumption of the smoothies. RESULTS. There was no difference in fasting blood glucose among subjects prior to drinking the smoothies (p = .92). The rise in blood glucose was significantly less at 50 minutes after consumption of the smoothies containing soy and whey protein in comparison to the control smoothie (p<.05), while at 120 minutes the soy and control were significantly lower than pea protein (p<.05). The blood glucose levels from the control smoothie at 50 to 120 minutes after consumption decreased significantly in comparison to all of the proteins additives. CONCLUSIONS. The addition of protein to smoothies has an effect on blood glucose response. Our study found that smoothies containing soy and whey proteins produced a lower glucose response from baseline to 50 minutes (96.4 mg/dL and 101.4 mg/dL, respectively) when compared to smoothies containing protein extracts from pea, milk, or the control (103.25 mg/dL, 103.3 mg/dL, and 118.0 mg/dL, respectively).

LLU Discipline

Nutrition and Dietetics


Nutrition and Dietetics


School of Allied Health Professions

First Advisor

Woosley, Kyndra

Second Advisor

Carter, James, III

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Postprandial periods; Blood glucose; Soyfoods; Dietary proteins; Dairy products; Vegetable proteins


Smoothies; Whey protein; Soy protein; Milk protein; Pea protein


Research Report

Page Count

19 p.

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Research Reports

Collection Website


Loma Linda University. University Libraries.