The purpose of this study is to determine whether consumption of carbonated drinks containing sweeteners affect insulin sensitivity.

Sweeteners are natural or synthetic sugar substitutes which provide a sweetness taste to drink and food with few or no additional calories. Sweeteners are widely used in commercialized beverages. Despite some debate, no significant toxicity was demonstrated at a reasonable level of consumption (less than 20 cans per day). However little data is available on the metabolic effects of a regular consumption of beverages containing sweeteners. The objective of the study is to evaluate the effect of a regular consumption (twice a day for 12 weeks) of a carbonated drink with sweeteners, in a normal diet, compared with unsweetened sparkling water on insulin sensitivity in healthy normoweight and overweight subjects.

Inclusion Criteria:

• Healthy male or female
• Subject taking at least three main meals (breakfast, lunch, dinner)
• Subject able to understand and sign an informed consent
• Subject drinking and enjoying soft drinks
• Subject appreciating sweeteners taste
• 19 kg/m² < BMI< 30 kg/m²

Exclusion Criteria:

• Any severe or acute illness that may influence the results of the study or may be life-threatening
• Pregnant or breastfeeding subject
• Past or present metabolic or digestive diseases, with the exception of a possible appendectomy
• Diabetes or severe acute illness that may alter blood sugar
• Treatment that may interfere with glucose homeostasis
• Past or present kidney disease (renal failure, ... )
• Local or systemic medication that may change water status, metabolism and feeding behavior
• Antiplatelet treatment
• Alcohol consumption ≥ 3-4 glasses / day ( ≥ 21 drinks / week )
• Sustained physical exercise (more than 4 hours per week)
• Subject adding sweeteners (tablets or powder) in their diet
• Subject drinking more than two cans of drinks with sweeteners / day
• Subject dieting to lose weight
• Subject unable or unwilling to consume 2 liters of fluid / day