Findings from The SWEET STUDY: Results from a 1-Year Randomized Controlled Trial

Study Finds Sweeteners Support Weight Loss Maintenance and Gut Health Without Cardiometabolic Harm

This study which investigated the efficacy and safety of combined and prolonged use of ‎sweeteners/sweetness enhancers‎ found in overweight or obese adults and children. It found that long-term use of sweeteners and sweetness enhancers supported better one-year weight loss maintenance and beneficial gut microbiota changes — without adverse effects on cardiometabolic health markers.

Study Overview

This multi-center, randomized, controlled trial aimed to assess the effect of combined and prolonged use of sweeteners and sweetness enhancers (S&SEs), in both foods and drinks, as part of a healthy sugar-reduced ad libitum diet on weight loss maintenance, cardiometabolic risk factors and gut microbiota composition in adults who are overweight or obese. In children who are overweight or obese, the trial focused on weight control (i.e. weight stability and maintenance of BMI-for-age z-score) and cardiometabolic outcomes. Adults followed a 2-month low-energy diet for ≥5% weight loss, followed by a 10-month healthy, casual diet with <10% energy from sugars. 

  • Group One (S&SEs group) – Replacement sugar-rich products with sweeteners and sweetness enhancer products
  • Group Two (Sugar group) – Consumed sugar-rich products 

Primary outcomes included changes in body weight and gut microbiota composition at 1 year. Secondary outcomes included changes in risk factors for Type 2 Diabetes and cardiovascular disease, body mass index (BMI)-for-age z-score, intrahepatic lipid (IHL) content, the occurrence of (serious) adverse events (AEs), gastrointestinal symptoms and use of concomitant medication in adults with overweight or obesity. 

Sugar Intake

In total, 203 adults and 22 children (60% and 58%) completed the 1-year trial. Overall, for all adults, total sugar intake was reduced by 12g/day, more in the S&SEs group than the sugar group. Both adults and children reduced their total intake of sugar-rich products by 142 g/day and 163 g/day, respectively. 

Weight Loss and Maintenance

The S&SEs group, compared to the sugar group, maintained greater weight loss at 1 year.

Gut Microbiota Composition

The S&SEs group, compared to the sugar group, exhibited distinct gut microbiota shifts, with increased short-chain fatty acid and methane-producing taxa. 

Other Outcomes

No significant differences were observed in risk factors for Type 2 Diabetes and cardiovascular disease, or in children. While the S&SE diet led to significantly larger decreases in BMI, total cholesterol, LDL-C, HDL-C and non-HDL-C at 6 months, only hip circumference was significantly more reduced in the S&SEs group than the sugar group at the one year mark. 

Key Takeaway

Overall, these findings indicate that, compared to adults consuming drinks and foods without S&SEs, those who included S&SEs in a healthy, sugar-reduced diet exhibited improved 1-year weight loss maintenance and gut microbiota composition without affecting cardiometabolic health markers. 

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