If you drink cola, sports drinks, or sweetened coffee daily, this matters. “Liquid sugar” turns out to hit body weight, diabetes risk, and liver fat harder than the same calories in solid form. Numbers and realistic swaps inside.
Conclusion: Sugary drinks are the single food item most clearly linked to an increased risk of type 2 diabetes, cardiovascular disease, and all-cause mortality.
[Level 1 (Strongest)] [Diet & Nutrition] [Strongly recommend limiting intake]
According to a systematic review by Frank Hu (Harvard T.H. Chan School of Public Health), sugar-sweetened beverages (such as cola, soda, sports drinks, sweetened coffee drinks, and sweetened tea) have been identified as the single food category most clearly associated with an increased risk of type 2 diabetes, cardiovascular disease, all-cause mortality, and cancer. Consuming one additional 350-milliliter can per day is associated with a 26% increase in the risk of type 2 diabetes.
📊 Effect Sizes and Key Studies
- Malik et al., Diabetes Care 2010 (Frank Hu’s laboratory): Meta-analysis of 11 cohorts, 310,000 participants. A daily intake of 1–2 servings was associated with a 26% increase in the risk of type 2 diabetes.
- Mullee et al., JAMA Internal Medicine 2019: 450,000 participants across 10 European countries; 16-year follow-up. Consuming two or more servings of sugar-sweetened beverages per day was associated with a 17% increased risk of all-cause mortality.
- Yang et al., JAMA Internal Medicine 2014: NHANES, approximately 30,000 participants. Strong dose-dependent relationship between the proportion of energy from added sugars and cardiovascular disease mortality (2.75-fold increase at 25% or higher).
- Dehghan et al., Lancet 2017 (PURE study): 130,000 participants across 18 countries. Countries with higher carbonated beverage consumption had higher cardiovascular disease mortality rates.
- Imamura et al., BMJ 2015: Meta-analysis of 17 cohorts. Each additional serving per day was associated with an 18% increase in the risk of type 2 diabetes (13% increase even after adjusting for BMI).
💡 The Bottom Line
Since liquid sugars do not promote a feeling of fullness, they can lead to excessive calorie intake. Rapid spikes in blood sugar → rapid spikes in insulin → fat accumulation. Fructose (including HFCS) is metabolized in the liver, leading to fatty liver disease and insulin resistance. It also poses a clear risk of tooth decay.
🎯 How to Start
The most effective approach is to break the habit of drinking it every day:
- Replace it with water, tea, black coffee, or unsweetened sparkling water.
- "100% fruit juice" has similar issues: it raises blood sugar faster than whole fruit and leaves you feeling less full. Limit it to about half a glass once or twice a week.
- "Zero-calorie, artificially sweetened" drinks will be discussed in a separate article (some studies suggest negative effects on metabolism). While far better than sugary drinks, they are not "healthy."
- Children’s habit of drinking sugary beverages is the biggest risk factor for future obesity and diabetes.
⚠️ Cautions
1. Sports drinks are also included: Aquarius and Pocari Sweat contain 15–20 g of sugar per 350 ml. They are unnecessary unless consumed after intense exercise.
2. “Café au lait,” “low-sugar,” and “calorie-reduced” products also contain sugar: Always check the label.
3. Energy drinks pose a double risk of caffeine and sugar (see separate article).
4. WHO recommended upper limit for added sugars: 5% or less of total energy intake (about 25g/day for adults). A 350ml can of cola contains 35g of sugar. One can exceeds the WHO limit.
📝 Summary
- Sugar-sweetened beverages are the single food category associated with the highest risk of type 2 diabetes, cardiovascular disease, and all-cause mortality (Level 1)
- One can a day increases the risk of type 2 diabetes by 26%
- Replacing them with water, tea, black coffee, or sugar-free sparkling water yields the greatest benefit
- Preventing children from developing a habit of consuming these drinks is particularly important
📚 References
- Malik VS, et al. Diabetes Care. 2010;33(11):2477-2483.
- Mullee A, et al. JAMA Internal Medicine. 2019;179(11):1479-1490.
- Yang Q, et al. JAMA Internal Medicine. 2014;174(4):516-524.
- Imamura F, et al. BMJ. 2015;351:h3576.
⚠️ Disclaimer
- This page is based on peer-reviewed scientific research, but it is not a substitute for medical care.
- Please consult a doctor or registered dietitian regarding individual health decisions.
