Effect of Carbonated Soft Drinks on the Body Weight

Study Overview
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Brief Summary
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Compared to solid foods, the nutritional energy of drinks may bypass the appetite regulation leading to obesity development. Although drinks sweetened with aspartame are available the anticipated positive effect of these drinks on obesity development has not been convincing. However, the mechanisms linking drinks intake to obesity are yet to be clarified. The investigators aim is to investigate the long-term effects of intake of soft drinks, milk and water. The study is a parallel, intervention trial with 80 overweight, healthy volunteers. They will be randomly selected to drink one liter a day of one of the four drinks for six months. The objectives are changes in numerous circulating metabolic risk factors, changes in body weight, anthropometric data and fat distribution (measured by DEXA, MRI and MR-spectroscopy). The investigators expect to clarify the mechanisms linking drinking habits to obesity development and provide scientifically based nutritional guidelines.

Official Title
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Effect of Carbonated Soft Drinks on Body Weight, Fat Distribution and Metabolic Risk Factors

Conditions
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Obesity, Metabolic; Complications, Dietary Habits

Intervention / Treatment
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* Other: Sugar-sweetened soft drink
* Other: Aspartame-sweetened soft drink
* Other: Semi-skimmed milk
* Other: Water


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 20-50 years; BMI between 28-36 kg/m2; Weight stabile 3 months prior to the study inclusion; Less than 10 hours of weekly exercise Exclusion Criteria: Diabetes Allergic to phenylalanine or milk Smoking Pregnancy or breast-feeding

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sugar-sweetened soft drink<br>54g sugar/L, 180kJ/100mL | Other: Sugar-sweetened soft drink<br>* One litre a day for six months.<br>|
| Experimental: Aspartame-sweetened soft drink<br>1.5kJ/100mL | Other: Aspartame-sweetened soft drink<br>* One litre a day for six months.<br>|
| Active Comparator: Semi-skimmed milk<br>202kJ/100mL | Other: Semi-skimmed milk<br>* One litre a day for six months<br>|
| Placebo Comparator: Water<br>0kJ/100mL | Other: Water<br>* One litre a day for six months.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body Weight (kg) |  | Six months | 
| MR spectroscopy | to assess liver fat and skeletal muscle fat | Six months | 
| Magnetic resonance imaging | to assess visceral adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAAT) | Six months | 
| Dual-energy X-ray absorptiometry (DEXA) scan | to assess total fat mass (kg), lean body mass (kg), and bone mass (kg) | Six months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure | Systolic and diastolic blood pressure (mmHg) | Six months | 
| Circulating metabolic parameters: including serum urate | mmol/L | Six months | 
| fasting plasma glucose | mmol/L | Six months | 
| fasting serum insulin | pmol/L | Six months | 
| Oral Glucose Tolerance Test (OGTT) | AUC OGTT glucose and insulin, AUC HOMA-IR, and Matzuda index | Six months | 
| Fasting blood lipids | Total, LDL, and HDL cholesterol, and TAG (mmol/L) | Six months | 
| Fasting plasma FFA | mmol/L | Six months | 
| Fasting plasma PAI-1 | ng/ml | Six months |