How to Quit Soda: A 4-Week Step-Down Plan (and How to Track It in Suu)
Published: September 27, 2026 · Furkan Mert Fındıklı · 7 min read
Short answer: The most reliable way to quit soda is to taper over 3–4 weeks rather than stop cold turkey: each week swap one daily can for sparkling water or a sugar-free drink, plan for the moments you usually reach for one, and expect a few days of caffeine headaches. Suu shows each can's sugar and its effect on your water goal in numbers.
Most people who try to quit soda go through the same loop: stop completely on Monday, cave on Wednesday afternoon with a headache and a sugar craving. It isn't a willpower problem. Soda delivers three things at once — sugar, caffeine and a habit moment (with lunch, during the afternoon slump, at the gas station on a long ride). Dropping all three in a single day is hard.
So the plan below doesn't ban soda. It tapers it over four weeks and makes every step measurable. First, a look at what one can actually is.
What's really in one can of soda?
A standard 12 fl oz (355 ml) can of cola has about 38 g of sugar — roughly 9½ teaspoons — and about 150 kcal. The World Health Organization recommends keeping free sugars below 10% of daily energy, and ideally below 5%, which is about 25 g.1 One can on its own is over that ideal limit. The NHS puts the adult maximum at 30 g of free sugars a day.2
Someone drinking a liter of soda a day gets around 106 g of sugar from drinks alone — four times the ideal limit.
Regular sugary drinks are linked to a higher risk of type 2 diabetes: a meta-analysis pooling eight cohort studies found that people drinking 1–2 servings a day had about a 26% higher risk than those drinking less than one a month.3
Why cold turkey fails: caffeine and habit
A can of cola has roughly 35 mg of caffeine; three cans come close to a cup of brewed coffee. When caffeine stops abruptly, headache, fatigue and poor concentration usually begin 12–24 hours after the last dose, peak on day one or two and can last 2–9 days.4 That's often why a Monday quit turns into a Wednesday relapse.
Habits change slowly too: in one study a new behavior took a median of 66 days to feel automatic, ranging from 18 to 254 days.5 Four weeks is a start, not the finish line — and one slip doesn't undo the plan.
The 4-week step-down plan
Make one change per week. If you drink less than a can a day, you can compress this into two weeks.
- Week 1 — measure: Change nothing; just log every can. Most people underestimate how much they drink, and the real number becomes your baseline.
- Week 2 — swap one can: Replace your most automatic can of the day (usually the one with a meal) with ice-cold sparkling water and a squeeze of lime. Keeping the fizz and the cold makes the swap feel smaller.
- Week 3 — ease off caffeine: Turn the afternoon can into the zero-sugar version or iced tea. Because caffeine doesn't drop to zero overnight, headaches are less likely.
- Week 4 — stop stocking it: Take soda out of the fridge. Having one when you're out is fine, but make it a decision, not the default.
- Every day: Drink a glass of water before the time you usually crave a soda, so the first thing within reach when you're thirsty is water.
Is diet soda a good replacement?
As a bridge, yes: it removes the sugar and calories while keeping the taste and fizz. But in 2023 the World Health Organization advised against using non-sugar sweeteners for weight control,6 and diet soda still contains caffeine and acid. The long-term goal is to shrink the sweet-drink habit itself — use diet soda as a bridge, not the destination.
Does soda count as water?
Partly. The fluid in soda counts, but not all of it. In Suu's calculation, cola enters with a hydration factor of 0.6, and its sugar raises your daily water need (+100 ml for every 10 g of sugar). Side by side, the difference is clear:
- Cola, 12 fl oz (355 ml): ~38 g sugar · ~210 ml counted as water · daily goal +375 ml
- Cola Zero, 12 fl oz: 0 g sugar · ~300 ml counted as water · goal unchanged
- Sparkling water, 12 fl oz: 0 g sugar · 355 ml counted as water · goal unchanged
These factors come from Suu's beverage catalog. They're not a scientific claim that "soda dehydrates you" — they're a calculation that keeps the end-of-day effect of a sugary drink realistic.
Where to track this in Suu
Every week of the plan has a place in the app. Menu names are exactly as they appear:
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Log the soda and see its real effect
iPhone: Home → quick add → Quick Drink → Cola
Android: Home → Add Beverage → ColaThe can is logged together with its sugar and its effect on your water goal. This is the "measure" step of week 1.
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Compare the swap
The same list: Cola Zero and Sparkling Water
See what the week 2 and week 3 swaps do in one place: sugar goes down, the amount counted as water goes up, and your goal stays put.
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Streak and Streak Freeze
The Streak indicator on the home screen
Every day you reach at least half of your water goal extends your streak. Each glass of water that replaces a soda feeds it, and if you miss a day, a Streak Freeze protects it.
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Smart Notifications
iPhone: Settings → Notification Settings → Smart Notifications
Android: Settings → Smart NotificationsGet a water reminder before the hours you usually crave soda, so the app handles the plan's "every day" step.
The short version
Don't try to quit soda in a day. Taper it over four weeks, swapping one can per week. Treat caffeine headaches as an expected, temporary side effect, use zero-sugar drinks as a bridge, and measure your progress.
Seeing the number makes the decision easier: one can of cola adds ~210 ml to your water while raising your daily goal by ~375 ml. Watching that gap every day quietly changes the "one can won't hurt" reflex.
See every can in numbers
Water, calories and workouts in one app · free on iOS and Android
Frequently asked questions
Is it better to quit soda cold turkey or gradually?
For most people a gradual taper is more sustainable, because caffeine withdrawal (headache, fatigue) and habit triggers don't all land on the same day. If you drink more than one can a day, cutting one can per week is a good pace.
Why do I get headaches when I stop drinking soda, and how long do they last?
It's caffeine withdrawal. Symptoms usually start 12–24 hours after your last caffeine, peak on day one or two and fade within 2–9 days. Tapering caffeine makes them milder; see a doctor if a headache lasts longer than a week or is severe.
Does diet soda count as water?
Partly. Most of its fluid counts — Suu uses a hydration factor of 0.85 for zero-sugar cola — but it contains caffeine and acid. It doesn't replace plain or sparkling water; it works best as a transition drink while you quit regular soda.
What can I drink instead of soda?
Ice-cold sparkling water with lime or mint, unsweetened iced tea, and plain water. If you mainly miss the fizz and the cold, sparkling water is the easiest switch.
How much sugar is in a can of Coke?
A standard 12 fl oz (355 ml) can of cola contains about 38 g of sugar, roughly 9½ teaspoons. That alone is above the World Health Organization's ideal daily limit of about 25 g.
How does Suu count soda?
Cola counts with a hydration factor of 0.6, and every 10 g of sugar raises your daily water goal by 100 ml. A 12 fl oz can counts as about 210 ml of water but raises your goal by about 375 ml.
References
- World Health Organization — Guideline: Sugars intake for adults and children (2015)
- NHS — Sugar: the facts
- Malik VS et al. — Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis. Diabetes Care, 2010
- Juliano LM, Griffiths RR — A critical review of caffeine withdrawal. Psychopharmacology, 2004
- Lally P et al. — How are habits formed: modelling habit formation in the real world. European Journal of Social Psychology, 2010
- World Health Organization — Use of non-sugar sweeteners: WHO guideline (2023)
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Suu is not intended for medical diagnosis or treatment. Consult a healthcare professional for health-related decisions.