Smoothies and Blood Sugars

NCT06333184 | Completed

• 1 other identifier: 3085-4215
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Glycaemic responses to fruit smoothies may depend on the food matrix (e.g., degree of processing and physical structure), ingestion rate, dose ingested and fibre content. Furthermore, the method of sampling could alter inferences. The aim of this project is to characterise how these factors affect the glycaemic response to a commercially available fruit smoothie. Participants will ingest 7 different test drinks in a randomised, crossover design with fingerstick capillary blood sampling alongside continuous glucose monitors. Test drinks will include a glucose reference (CONTROL), the commercial product matched for carbohydrate to CONTROL (PRODUCT), equivalent carbohydrate ingested as whole fruits (WHOLE), equivalent carbohydrate ingested as blended fruits (WHOLE), equivalent carbohydrate as the commercial product ingested slowly (SLOW), equivalent carbohydrate as the commercial product ingested with additional fibre (FIBRE), and the commercial product ingested in a dose typically bought (DOSE). These data will provide insight into how the food matrix and different patterns of ingestion can alter the glycaemic response to a fruit smoothie, and how the measurement method may alter interpretations.

Conditions

Metabolic Disturbance

Outcome Measures

Primary Outcomes (1)

• Glycaemic index of product with capillary vs CGM

  The difference in glycaemic index \[2-hour incremental area under the curve (mmol/L-1x120 min) for PRODUCT relative to CONTROL expressed as a percentage\] in capillary blood samples versus continuous glucose monitors.

  120 min

Secondary Outcomes (1)

• Glycaemic index of all conditions with capillary vs CGM

  120 min

Other Outcomes (5)

• Condition-by-sampling interaction

  120 min

• GI of products in capillary samples

  120 min

• GI of products in continuous glucose monitors

  120 min

Study Arms (7)

Control

ACTIVE COMPARATOR

50 g glucose (55 g dextrose powder accounting for hydration) plus 417 mL water

Other: Food

Product

EXPERIMENTAL

417 mL of commercially available "Mango \& Passion fruit" fruit smoothie providing 50 g carbohydrate

Other: Food

Whole

EXPERIMENTAL

Apples (51%), Mango (16%), Banana (16%), Orange (12%), Passionfruit (3%), Peach (2%), Lime (0.4%; recipe matched to PRODUCT) eaten as whole fruit with added water as needed to match volume.

Other: Food

Blend

EXPERIMENTAL

Apples (51%), Mango (16%), Banana (16%), Orange (12%), Passionfruit (3%), Peach (2%), Lime (0.4%; recipe matched to PRODUCT) eaten as blended fruit with added water as needed to match volume.

Other: Food

Slow

EXPERIMENTAL

417 mL of commercially available "Mango and Passionfruit" fruit smoothie providing 50 g carbohydrate ingested slowly over 25-35 mins.

Other: Food

Fibre

EXPERIMENTAL

417 mL of commercially available "Mango and Passionfruit" fruit smoothie providing 50 g carbohydrate with 6 g of added inulin.

Other: Food

Dose

EXPERIMENTAL

250 mL of commercially available "Mango and Passionfruit" fruit smoothie providing 30 g carbohydrate.

Other: Food

Interventions

Food OTHER

Fruit ingested in whole form or as either commercially available, or home-made smoothies

Blend; Control; Dose; Fibre; Product; Slow; Whole

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age: 18-65 years
• Body mass index 18-30 kg/m2

You may not qualify if:

• diagnosis of any form of diabetes
• intolerances or allergies to any of the study procedures (e.g. fructose/inulin intolerance)
• Fructose malabsorption
• Inborn errors of fructose metabolism (e.g. fructokinase deficiency, aldolase B deficiency, fructose-1,6-bisphosphatase deficiency)
• pregnant or lactating
• any condition that could introduce bias to the study (e.g. diagnoses of lipid disorders, including cardiovascular disease, or therapies that alter lipid or glucose metabolism, such as statins or niacin).

Sponsors & Collaborators

• University of Bath: lead

Study Sites (1)

Department for Health, University of Bath

Bath, BA2 7AY, United Kingdom

Location

Related Publications (2)

• Gonzalez JT. Are all sugars equal? Role of the food source in physiological responses to sugars with an emphasis on fruit and fruit juice. Eur J Nutr. 2024 Aug;63(5):1435-1451. doi: 10.1007/s00394-024-03365-3. Epub 2024 Mar 16.

  PMID: 38492022 BACKGROUND

• Hutchins KM, Betts JA, Thompson D, Hengist A, Gonzalez JT. Continuous glucose monitor overestimates glycemia, with the magnitude of bias varying by postprandial test and individual - a randomized crossover trial. Am J Clin Nutr. 2025 May;121(5):1025-1034. doi: 10.1016/j.ajcnut.2025.02.024. Epub 2025 Feb 26.

  PMID: 40021059 DERIVED

MeSH Terms

Interventions

Food

Intervention Hierarchy (Ancestors)

Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Nutrition and Metabolism

Study Record Dates

• First Submitted: March 20, 2024
• First Posted: March 27, 2024
• Study Start: March 20, 2024
• Primary Completion: August 30, 2024
• Study Completion: August 30, 2024
• Last Updated: September 19, 2024

Record last verified: 2024-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: These will become available at the point of publication permanently.

Locations

GB (1)