Effects on weight loss in adults of replacing diet beverages with water during a hypoenergetic diet: a randomized, 24-wk clinical trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 26537940 · doi:10.3945/ajcn.115.109397
What was done
In a 24-week randomized trial, 89 overweight and obese women (BMI 27–40 kg/m², age 18–50 years) who were habitual consumers of diet beverages were assigned during a hypoenergetic weight-loss program to either replace diet beverages with water (water group) or continue consuming diet beverages 5 times per week after lunch (diet beverage group). Anthropometric and cardiometabolic variables were assessed, and 62 participants completed the 24-week trial.
What was found
Both groups lost weight and improved cardiometabolic markers, but the water group achieved a significantly greater reduction in body weight compared with the diet beverage group (mean ± SD: -8.8 ± 1.9 kg vs -7.6 ± 2.1 kg; P = 0.015). The water group also showed greater decreases in fasting insulin (-2.84 ± 0.77 vs -1.78 ± 1.25 mU/L; P < 0.001), HOMA-IR (-0.097 ± 0.049 vs -0.057 ± 0.042; P < 0.001), and 2-hour postprandial glucose (-1.02 ± 0.25 vs -0.72 ± 0.27 mmol/L; P < 0.001). No significant time-by-group interactions were observed for waist circumference, fasting plasma glucose, or lipid profiles.
Why it matters
This study shows that substituting plain water for artificially sweetened beverages during a calorie-restricted diet produces modest additional weight loss and improved glycemic markers.
Limits
The study enrolled only women aged 18 to 50, limiting generalizability to men and older populations. Attrition was high, with 29% (27/89) dropping out before study completion. Beverage replacement was restricted to a single daily meal (lunch) 5 days per week, and blinding of participants to the beverage intervention was not possible.
Cited by
- contradicts Randomized controlled trials and meta-analyses comparing substituting regular soda with water versus diet soda found that diet soda resulted in greater weight loss than water.