Yes, you can drink soda while breastfeeding. An occasional soda is not harmful to your baby, but the caffeine, sugar, and artificial sweeteners in soda all transfer to breast milk in small amounts, so moderation matters. The main concern is caffeine: the CDC considers up to 300 milligrams per day safe during breastfeeding, and most sodas contain far less caffeine per can than a cup of coffee.
How Much Caffeine Is in Soda
A standard 12-ounce can of soda contains considerably less caffeine than coffee. Here’s how the most popular options compare:
- Mountain Dew: 55 mg
- Dr Pepper: 41 mg
- Pepsi: 37.5 mg
- Coca-Cola Classic: 34 mg
For context, a typical 8-ounce cup of coffee has around 95 mg. So even two cans of Coke deliver less caffeine than a single cup of coffee. Caffeine-free versions of most sodas are also widely available and eliminate this concern entirely.
How Caffeine Reaches Your Baby
Caffeine passes into breast milk and typically peaks about one hour after you drink it. An exclusively breastfed infant receives roughly 7 to 10 percent of the mother’s weight-adjusted caffeine dose, which is a small fraction. At moderate intake levels (300 mg per day or less), this amount generally does not cause problems.
Where things change is at very high intake. Fussiness, jitteriness, and poor sleep patterns have been reported in infants whose mothers consumed the equivalent of 10 or more cups of coffee per day. In one documented case, a mother drinking 4 to 5 cups of coffee plus two to three large bottles of cola daily had an infant with trembling and increased muscle tone, though the baby was still gaining weight normally. In an extreme case involving 20 cups of coffee per day, the infant showed restlessness and irritability.
Newborns are more sensitive than older babies because they process caffeine much more slowly. A premature or very young infant can take days to clear the same amount of caffeine that a 6-month-old metabolizes in hours. If your baby seems unusually fussy or isn’t sleeping well and you’re drinking multiple caffeinated beverages per day, cutting back is a reasonable first step.
Sugar in Regular Soda
A 12-ounce can of regular soda contains about 39 grams of sugar, which is close to the entire daily added-sugar limit recommended for adults. While the sugar itself doesn’t pass directly into breast milk in a way that sweetens it, high sugar intake affects your overall nutrition and energy levels during a period when your body needs quality fuel to produce milk.
Breastfeeding burns roughly 500 extra calories per day. Filling that caloric need with sugary drinks means fewer nutrients reaching you and your baby. There’s also a longer-term consideration: the dietary habits you build during breastfeeding tend to shape the foods and drinks available in your household as your child grows. Research has found that children ages 1 to 5 who consume more than three servings of sugar-sweetened beverages per day have significantly higher odds of obesity compared to those who drink one serving or less.
Diet Soda and Artificial Sweeteners
If you’re reaching for diet soda instead, the sweeteners do make their way into breast milk, though the picture varies by type. A study measuring breast milk after diet soda consumption found that acesulfame-potassium appeared almost immediately, while sucralose showed up about two hours later. Saccharin also transfers into breast milk. Aspartame, on the other hand, was not detected in breast milk samples, likely because it breaks down before reaching the bloodstream in significant amounts. One exception: mothers of infants with phenylketonuria (PKU), a rare metabolic condition, are advised to avoid aspartame since it breaks down into phenylalanine, which these babies cannot process.
The concentrations of these sweeteners found in breast milk are low, and current evidence does not point to immediate harm. However, the long-term effects of exposing infants to artificial sweeteners through breast milk remain unstudied. One concern researchers have raised is that because babies have an innate preference for sweetness, repeated exposure to sweet-tasting compounds in breast milk could shape their taste preferences toward sweeter foods and beverages later on. Given these unknowns, limiting diet soda rather than drinking it freely is a reasonable approach.
Hydration During Breastfeeding
Breastfeeding makes you thirstier than usual because your body is using extra fluid to produce milk. The general recommendation is to drink an 8-ounce glass of water, juice, or milk at each meal and every time you nurse. Soda is a poor substitute for this. Caffeinated drinks have a mild diuretic effect, and the sugar or artificial sweeteners don’t offer the hydration benefit that plain water does.
This doesn’t mean you can never grab a soda. It means soda shouldn’t be your go-to for staying hydrated. If you’re relying on it to get through a long day, swapping most of those servings for water and keeping soda as an occasional treat will better support your milk supply and your own recovery.
Practical Guidelines for Soda Intake
Keeping your total caffeine under 300 mg per day is the clearest benchmark. With most sodas containing 34 to 55 mg per can, you’d need to drink six or more cans to approach that limit from soda alone. The more realistic concern is when soda is layered on top of coffee, tea, or chocolate, all of which also contain caffeine. If you have a cup of coffee in the morning and a soda in the afternoon, you’re well within safe range.
If you notice your baby is unusually restless, sleeping in shorter stretches, or seems jittery, try cutting caffeine for a few days to see if the pattern changes. Younger infants under 3 months are more likely to show sensitivity. By 6 months, most babies can handle the small amounts of caffeine that come through breast milk without any noticeable effect.
For sugar-sweetened soda, one can a day is unlikely to cause problems, but making it a several-cans-a-day habit can crowd out the nutrition your body needs during lactation. For diet soda, the same general moderation applies, with the added note that the sweeteners do reach your baby in small, still-not-fully-understood amounts.