Effect of a Protein Supplementation on Body Weight and Metabolic Variables in Overweight and Obese Patients

This study compares the effects of two calorie-restricted diets-one with whey protein supplementation and one without-and a health education control group on weight and metabolic parameters in overweight and obese individuals, with the aim of informing dietary intervention strategies for this population.

Study Overview

• Status: Completed
• Conditions: Obesity; Overweight
• Intervention / Treatment: Dietary supplement: whey protein powder; Behavioral: calorie-restricted balanced diet; Behavioral: health education

Detailed Description

The prevalence of overweight and obesity has been rising globally due to lifestyle and dietary changes. According to the "Report on the Status of Nutrition and Chronic Diseases among Chinese Residents (2020)", the proportion of overweight and obese adults in China has exceeded 50%. Overweight and obesity are not only major risk factors for chronic diseases such as diabetes and cardiovascular diseases but are also closely related to the increased risk of premature death. They have become one of the most serious public health problems.

Dietary intervention is a fundamental approach to the treatment of overweight and obesity. In recent years, the impact of different dietary structures on overweight and obesity has received increasing attention from researchers. The "Chinese Guidelines for Medical Nutrition Therapy of Overweight/Obesity (2021)" points out that a high-protein diet can reduce hunger, increase satiety, and increase resting energy expenditure, which is beneficial for weight loss and improving glucose homeostasis and blood lipid levels in overweight and obese patients. Studies have shown that increasing dairy intake during energy-restricted dietary intervention may help enhance satiety and reduce more body weight and fat mass. Whey protein is the protein component retained in the supernatant during the separation and precipitation of casein, and it is rich in essential amino acids. The proportion of branched-chain amino acids in its amino acid composition pattern is relatively high, which can promote the construction and repair of human tissue structure. Studies have shown that whey protein supplements can help overweight and obese patients lose weight and body fat, maintain lean body mass, and to some extent improve cardiovascular disease risk factors such as blood pressure and blood glucose levels. However, the potential mechanisms of action are not clear. In addition, the role of whey protein in the overweight and obese population in China remains to be studied. Based on this, this project designed two dietary models: a whey protein powder-supplemented energy-restricted high-protein diet and an energy-restricted balanced diet. They were compared with a health education control group to study the effects of whey protein powder on weight and metabolic indicators in overweight and obese patients, in order to provide a reference for dietary intervention in overweight and obese patients.

• Study Type: Interventional
• Enrollment (Actual): 110
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310009
      • The Second Affiliated Hospital, Zhejiang University School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 25-35 years old, no gender restrictions
• Body mass index (BMI) ≥ 24 kg/m²
• Voluntary consent and signed informed consent form

Exclusion Criteria:

• Age < 25 years or > 35 years
• Current use of medications that may affect weight or energy balance (e.g., lipid-lowering drugs, antidiabetic drugs, appetite suppressants), or other protein supplements
• Presence of acute or chronic viral hepatitis, abnormal liver function (ALT or/and AST > 3 times the upper limit of normal), kidney disease (serum creatinine > upper limit of normal), diabetes, malignant tumors, or cardiovascular diseases
• Gastrointestinal disorders that affect food digestion and absorption (e.g., chronic diarrhea, constipation, severe gastrointestinal inflammation, active peptic ulcer disease, post-gastrointestinal surgery)
• Psychiatric disorders
• Allergies to product ingredients or presence of inborn metabolic disorders
• Pregnancy or lactation
• Other conditions deemed unsuitable for participation in the study by the researchers (e.g., severe diseases not listed in the exclusion criteria)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Whey protein group; Participants in the whey protein group underwent a 30% reduction in their average energy intake. They consumed whey protein powder twice daily (13 grams each) with breakfast and afternoon snacks, partially replacing staple foods. The macronutrient distribution for this group was as follows: Carbohydrates: 45%-50% of energy intake Protein: 20%-25% of energy intake Fat: 30% of energy intake The energy-restricted diet lasted for 12 weeks. During this period, clinical nutritionists monitored participants' dietary intake and exercise habits twice a week via WeChat/phone calls. Participants had outpatient visits every 4 weeks for dietary and exercise monitoring and guidance.	Dietary supplement: whey protein powder; The intervention period lasted for 12 weeks. During this time, Participants received dietary guidance from researchers. The whey protein group underwent a 30% energy reduction diet with a macronutrient distribution of 45%-50% carbohydrates, 30% fat, and 20%-25% protein. Participants consumed 13 grams of whey protein powder twice daily, with breakfast and afternoon snacks, partially replacing staple foods.
Active Comparator: Calorie-restricted balanced diet group; Participants in the energy-restricted balanced diet group underwent a 30% reduction in their average energy intake. The macronutrient distribution for this group was as follows: Carbohydrates: 55% of energy intake Protein: 15% of energy intake Fat: 30% of energy intake The energy-restricted diet lasted for 12 weeks. During this period, clinical nutritionists monitored participants' dietary intake and exercise habits twice a week via WeChat/phone calls. Participants had outpatient visits every 4 weeks for dietary and exercise monitoring and guidance.	Behavioral: calorie-restricted balanced diet; The intervention period lasted for 12 weeks. During this time, Participants received dietary guidance from researchers. The calorie-restricted balanced diet group underwent a 30% energy reduction diet with a macronutrient distribution of 55% carbohydrates, 30% fat, and 15% protein.
Active Comparator: Health education control group; Participants in the health education control group followed an unrestricted energy healthy diet plan. The macronutrient distribution for this group was as follows: Carbohydrates: 50%-65% of energy intake Protein: 10%-15% of energy intake Fat: 20%-30% of energy intake The intervention lasted for 12 weeks. During this period, clinical nutritionists monitored participants' dietary intake and exercise habits twice a week via WeChat/phone calls. Participants had outpatient visits every 4 weeks for healthy diet and exercise guidance.	Behavioral: health education; The intervention period lasted for 12 weeks. During this time, Participants received dietary guidance from researchers. The health education control diet group followed an unrestricted energy healthy diet plan with a macronutrient distribution of 50% -65%carbohydrates, 20%-30% fat, and 10%-15% protein.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body weight	Measured after fasting and voiding, without shoes, in light clothing, using a standard scale	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skeletal muscle mass	Measured by Bioelectrical impedance analysis	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention
Body fat mass	Measured by Bioelectrical impedance analysis	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention
Body fat percentage	Measured by Bioelectrical impedance analysis	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention
Visceral fat area	Measured by Bioelectrical impedance analysis	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention
Handgrip strength	Measure the grip strength of the dominant hand, take the maximum value of two attempts, and record to the nearest 0.1 kg	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention
Fasting glucose level	Collect fasting venous blood (after at least 8 hours of fasting) from subjects to measure fasting blood glucose	Change from baseline to 12 weeks
Insulin-resistance status	Measured with the use of the homeostasis model assessment of insulin resistance (HOMA-IR)	Change from baseline to 12 weeks
Fasting insulin	Collect fasting venous blood (after at least 8 hours of fasting) from subjects to measure fasting insulin	Change from baseline to 12 weeks
Serum lipids	Fasting venous blood (after 8 hours of fasting) is collected from the subjects. Serum levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) are measured	Change from baseline to 12 weeks
Renal function	Collect fasting venous blood (after at least 8 hours of fasting) from subjects to measure serum creatinine (Cr) and blood urea nitrogen (BUN) . The estimated glomerular filtration rate (eGFR) is calculated using the CKD-EPI or MDRD formula based on serum creatinine, age, sex, and race.	Change from baseline to 12 weeks
Hunger rating	Using a 5-point Likert scale (Not at All, Somewhat, Moderately, Very, Extremely)	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention
Diet Satisfaction	Using a 5-point Likert scale (Not at All, Somewhat, Moderately, Very, Extremely)	Baseline; after 4-week intervention; after 8-week intervention；after 12-week intervention

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

Study Major Dates

• Study Start (Actual): February 23, 2024
• Primary Completion (Actual): October 17, 2024
• Study Completion (Actual): October 17, 2024

Study Registration Dates

• First Submitted: August 8, 2024
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 24, 2026

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 17, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Whey Protein; Overweight and Obesity; Dietary Pattern
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity
• Other Study ID Numbers: 2022-0930

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No