It surprises people, but one of the more consistent everyday reports from those who cut carbohydrate is that their heartburn settles down. Gastro-oesophageal reflux disease, or GERD, is the chronic version of that burning discomfort when stomach acid rises into the gullet, and a growing handful of studies suggest that eating fewer carbs can genuinely help. The evidence is still young, but it points the same way.
What the studies show
A 2024 review pulled together the research on low-carbohydrate and ketogenic diets for reflux and found that all five of the studies it identified reported relief of GERD symptoms and a measurable drop in how long the lower gullet was exposed to acid, at least in the short term. One small prospective study found that after a month on a ketogenic diet, acid exposure higher up the gullet fell significantly and every patient reported a better reflux quality-of-life score. This builds on an older, often-cited study from 2006 in which people with GERD who went on a very-low-carbohydrate diet saw both their symptoms and their measured acid exposure improve. The studies are small, but they are unusually consistent.
Why it might work
There are a few plausible reasons. Carbohydrate that is not fully absorbed can be fermented by gut bacteria, producing gas that raises pressure in the stomach and can push acid upward, so eating less of it may mean less of that pressure. Carbohydrate-rich meals have also been linked to more frequent relaxations of the valve at the top of the stomach, the lapse that lets acid escape. And there is a simpler factor sitting underneath all of it: excess weight, particularly around the middle, is a major driver of reflux, and low-carb diets reliably produce weight loss, which eases the mechanical pressure on the stomach. It is likely a combination of all three rather than one clean mechanism.
The honest caveats
A few things keep this in proportion. The studies are small and short, running from days to a few months, so we cannot yet say much about the long term. It also may not take strict keto to get the benefit; a moderately lower-carb diet might be enough for many people, since the studies vary in how restrictive they were. And there is a wrinkle worth knowing: a minority of people actually notice more reflux when they first start keto, because very fatty meals can slow stomach emptying and trigger symptoms in some individuals. If that happens, easing back on the heaviest, fattiest meals while keeping the carbs low often settles it.
What it means in practice
If you suffer from reflux and are considering low-carb anyway, the research offers a reasonable hope that it will help, and many people find it does. Pay attention to your own response over a few weeks, since this is one area where individual variation is large. Keep meals from being enormous, do not eat late at night, and notice whether very fatty meals specifically set you off. If your reflux is frequent or severe, it still warrants proper medical assessment rather than diet alone, because persistent reflux can have causes and consequences that need looking at. Diet is a sensible lever to pull, not a replacement for that.
The bottom line
Across several small but consistent studies, cutting carbohydrate eased reflux symptoms and reduced measured acid exposure, probably through a mix of less gas-producing fermentation, fewer valve relaxations and weight loss. It is promising rather than proven, strict keto may not be necessary, and a few people react the other way at first. For a great many reflux sufferers, though, fewer carbs is one of the more pleasant side effects of low-carb eating.
This is general information about the ketogenic diet, not medical advice. Persistent acid reflux should be assessed by a doctor, because it can have serious causes. Do not stop any prescribed reflux medication without medical advice, and if you are pregnant, on medication, or managing a health condition, speak to a professional before changing your diet.
Source: Latorre-RodrÃguez AR, Munir S, Mittal SK. Effect of Ketogenic Diet on Gastroesophageal Reflux Disease: Literature Review and Exploratory Study. Foregut. 2024. Read it here. See also the earlier very-low-carbohydrate study here.