Impact of Whey and Soy Protein Ingestion in Conjunction With Energy Restriction in Overweight/Obese Individuals

Not Applicable

Completed

• Conditions: Obesity
• Interventions: Behavioral: Weight loss; Dietary Supplement: Whey; Dietary Supplement: Soy

• Registration Number: NCT01530646
• Lead Sponsor: McMaster University

Brief Summary

It is known that dieting (restricted energy intake) without resistance training leads to a reduced metabolic rate, and the loss of both fat and muscle mass. When exercise is not included in a period of restricted energy intake, the degree to which muscle mass is lost is highly dependent upon protein consumption. Whey protein is a high quality protein isolated from milk and is known to stimulate new protein synthesis for all proteins in your body. Previous research has established that the consumption of whey protein has been correlated with retaining muscle mass while stimulating fat loss. However, the mechanisms behind these findings is still unknown. The purpose of this study is to establish a mechanistic underpinning to the efficacy of whey protein versus soy protein and a carbohydrate control (maltodextrin), in promoting fat mass loss and lean mass retention during a period of short-term controlled dietary energy deficit (-750 kcalories/day).

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2011-08-04
• Study Start: 2012-02
• Study First Submitted QC: 2012-02-07
• Study First Posted: 2012-02-10
• Primary Completion: 2013-02
• Study Completion: 2013-05
• Status Verified: 2015-06
• Last Update Submitted: 2015-06-06
• Last Update Posted: 2015-06-09

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 42

Inclusion Criteria

• Aged 35 to 55 years old
• Moderately Obese/Overweight (body mass index > 25 and < 42 kg/m2)
• Healthy
• Non-smoker

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Exclusion Criteria

• Suffer from type 2 diabetes, hyperlipidemia, or thyroid dysfunction
• Taking medications
• Having an unstable weight in the past 4-6 months, or dieting at some time during the past 6 months
• Taking weight loss products or aids (including energy drinks)

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Whey	Weight loss	Whey protein \& 750 kcal dietary restriction while they receive a daily supplement (2 x 25 g) of WPI for 14 days. Weight loss.
Whey	Whey	Whey protein \& 750 kcal dietary restriction while they receive a daily supplement (2 x 25 g) of WPI for 14 days. Weight loss.
Soy	Weight loss	Soy protein \& 750 kcal dietary restriction while they receive a daily supplement (2 x 25 g) of SPC for 14 days. Weight loss.
Control	Weight loss	Carbohydrate \& 750 kcal dietary restriction while they receive a daily supplement (2 x 25 g) of maltodextrin (no protein) for 14 days. Weight loss.
Soy	Soy	Soy protein \& 750 kcal dietary restriction while they receive a daily supplement (2 x 25 g) of SPC for 14 days. Weight loss.

Primary Outcome Measures

Name	Time	Method
Muscle protein synthesis rate and lipolytic rate as measured using stable isotope and glycerol infusions.	After 14 day dietary intervention

Secondary Outcome Measures

Name	Time	Method
Transcriptomic changes (via gene profiling) associated with the effects of whey on lipogenic and lipid oxidative genes, and protein synthetic pathways in muscle.	After 14 days of dietary intervention

Trial Locations

Locations (1)

McMaster University; 🇨🇦 Hamilton, Ontario, Canada