What Happens To Your Body If You Start Eating Dairy Again?

If it’s been ages since you splashed actual milk into your coffee or enjoyed a cheese plate, then the mere idea of eating dairy again might make your stomach gurgle. And yet, there are rumblings on TikTok about milk and its benefits... so much so that — gasp — people are having whole glasses of the stuff.

It’s clear that over the past 10 to 20 years milk has become less popular, which is why plant-based alternatives have become such a massive industry. Beyond the countless alt-milks that exist, you can find everything from plant-based cheeses to sour cream and everything in between. Having all these options is great if you’re vegan, have lactose intolerance or a dairy allergy, or if you simply don’t like the taste of real cheese but still really, really want to make a pizza. If you’re someone who instantly bloats if you even look at a milkshake, then it makes total sense to continue on with your dairy-free life.

If you didn’t cut cheese and milk out of your diet for health reasons, however, and are curious about what might happen if you start eating dairy again, read on for what the experts say.

What Happens If You Eat Dairy Again?

When you consume yogurt or drink a glass of milk after ditching dairy for a long time, the most likely side effect will be gastrointestinal (GI) distress, aka lots and lots of bubbles. “Dairy contains the carbohydrate lactose, which is broken down by the enzyme lactase,” says Cara Harbstreet, MS, RD, LD, a registered dietician with Street Smart Nutrition. If it’s been months or years since you last had dairy, your body’s lactase production may be lower now than it was back then, she says, and there’s no telling whether it’ll be a temporary or permanent change.

If you used to handle dairy OK, then you might experience side effects for the first time after taking a break. But if you’ve always had issues with milk, those side effects will likely come rushing back. These include GI-related issues like bloating, gas, or changes in your bowel movement frequency or consistency as your body deals with the increased lactase production, Harbstreet says. “While this doesn’t pose a health threat, it is arguably quite uncomfortable to experience,” she adds.

Other factors that might impact how well you tolerate dairy include your age, genetics, and how long it’s been since your last time eating it. It’s important to note that the body gradually decreases its lactase production as you age whether you give up milk or not, so that also may explain why your body suddenly starts to react poorly to dairy.

According to Harbstreet, it’s near impossible to pinpoint the cause-and-effect relationship for a single food when symptoms show up or resolve. “But that also means we can tailor our food choices to best reflect what our individual bodies respond to at any given point in time,” she says.

How Long Will It Take To Adjust To Dairy?

Everybody’s reaction to dairy after a break will be different. It’s possible you’ll throw back a latte or eat an entire soft serve ice cream cone and not feel a thing. If you do experience gas or bloating as your body adjusts, the symptoms might go away quickly, Harbstreet says — or you might remember why you hated milk in the first place.

If you want to see if dairy will work for you, give it about two days after your first taste. “If you experience intolerance symptoms with dairy consumption, these should resolve within 48 hours of avoiding dairy intake,” says Kristin Gillespie, MS, RD, LDN, a registered dietitian and certified nutrition support clinician. She recommends keeping a food/symptom journal to track the process so you can see in real time whether milk does or does not work for you. “If you identify dairy as the culprit, it is best to change over to a plant-based milk product to control your symptoms,” Gillespie says.

Go slow if you’re determined to reintroduce the food group into your life. “Start with small servings,” Harbstreet says. “It doesn’t have to involve gulping down cups of milk; you might add it in a recipe or try dairy in forms like cheese, yogurt, sour cream, or butter.”

Cheeses and butters all have varying levels of lactose, she notes. And some, such as yogurt or fermented dairy foods like kefir, may even lessen your GI symptoms. “Experimenting with smaller amounts can help you find the threshold for when or if these symptoms pop up,” Harbstreet says. It’s all up to you to decide if you’re down with almond milk or if that cheese plate is too good to ignore.

Studies referenced:

Alves, E. (2022). Kefir and the Gut-Skin Axis. Int J Environ Res Public Health. doi: 10.3390/ijerph192113791.

Anguita-Ruiz, A. (2020). Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies. Nutrients. doi: 10.3390/nu12092689.

Forsgård, R. A. (2019). Lactose digestion in humans: intestinal lactase appears to be constitutive whereas the colonic microbiome is adaptable. The American Journal of Clinical Nutrition, 110(2), 273-279. https://doi.org/10.1093/ajcn/nqz104

Grand, R. J. (2003). Changing genes; losing lactase. Gut, 52(5), 617-619. https://doi.org/10.1136/gut.52.5.617

Sethi, S. (2016). Plant-based milk alternatives an emerging segment of functional beverages: a review. J Food Sci Technol. doi: 10.1007/s13197-016-2328-3.

Stefano, M.D. (2001). Lactose malabsorption and intolerance in the elderly. Scand J Gastroenterol. PMID: 11761016 DOI: 10.1080/003655201317097119

Swagerty, DL Jr. (2003). Lactose intolerance. Am Fam Physician. 2002 May 1;65(9):1845-50. Erratum in: Am Fam Physician. PMID: 12018807.

Szilagyi, A. (2018). Lactose Intolerance, Dairy Avoidance, and Treatment Options. Nutrients, 10(12). https://doi.org/10.3390/nu10121994

Sources:

Cara Harbstreet, MS, RD, LD, registered dietician with Street Smart Nutrition

Shena Jaramillo MS, RD, registered dietician

Kristin Gillespie, MS, RD, LDN, registered dietitian, certified nutrition support clinician