The Study
The effects of low-calorie sweeteners on energy intake and body weight: a systematic review and meta-analyses of sustained intervention studies
This study looked at lots of experiments where people swapped sugary drinks for diet ones — and found that, on average, people lost a little weight. But if they drank diet drinks instead of water, they didn’t lose weight. So it’s not that diet drinks make you lose weight — it’s that they help when you stop drinking sugar.
Analysis score
Maximum 100 for a systematic review with meta-analysis.
Where the score came from
If you swap sugary drinks for diet ones, you might lose a little weight. But if you drink diet drinks instead of water, or swallow sweetener pills without tasting them, you won’t lose weight.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 553 / 100
Quality score
The highest quality evidence. Systematic reviews and meta-analyses that pool randomized controlled trials, giving the most reliable summary of experimental evidence.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Losing 1 kg is modest but meaningful over time, especially if you replace a lot of sugary foods/drinks.
- 2It’s not a magic fix, but helps when used to cut sugar.
- 3Losing 1.06 kg on average when replacing sugar with diet sweeteners.
- 4No weight change when replacing water or taking capsules without tasting.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
International Journal of Obesity
Year
2020
Authors
P. Rogers, K. Appleton
Related Content
Claims (6)
If you swap sugary foods and drinks for ones with artificial sweeteners, you might lose about 1 kg and eat fewer calories—especially if you cut out a lot of sugar. But this only works if you’re replacing sugar, not just adding sweeteners on top.
If you drink diet soda instead of water or nothing, it won’t help you lose weight or eat less — but if you swap it for sugary drinks, then it might help.
If you swallow sugar-free sweeteners in a pill without tasting them, your weight doesn’t change consistently—so it’s not the sweet taste that affects weight, but rather whether you eat fewer calories overall.
When you use sugar-free sweeteners instead of sugar, the more sugar you replace, the more weight you tend to lose—this suggests that cutting calories by swapping sugar is why you lose weight.
Using sugar substitutes like stevia or aspartame doesn’t make you more likely to have bad health effects than eating sugar, drinking water, or taking a fake pill—so they’re probably safe if you’re trying to lose weight.
When people eat or drink things with low-calorie sweeteners like they normally do, studies show it doesn’t hurt their health.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.