By the time I saw my fourth pain specialist, I’d been eating keto for a while. He was the first doctor to raise diet as something that could matter for pain. Specialist number three had been firmly against it, and couldn’t tell me why.
So I went looking. This guide covers what keto actually is, what the research on keto and pain management says so far, where it runs out, and how I’d start if you’re curious. The short version is interesting, early and not a cure.
The short version
- Keto is a way of eating: high fat, moderate protein, very low carb. It isn’t a treatment.
- Most of the evidence on keto and pain comes from rodents. Human evidence is thinner, and CRPS-specific evidence thinner again.
- If you want to try it, change one thing at a time, keep a food diary and loop in your GP or an Accredited Practising Dietitian.
What I mean by keto
There are a lot of weird and wonderful ideas about what keto is. It got popular in the weight-loss world, which has been a double-edged sword. Lion diet, carnivore, strict keto, dirty keto, whatever else is out there this week: I’ve untangled the jargon in Keto vs Low Carb: What’s the Difference? so I won’t do it again here.
At its core, keto is eating within certain macro ratios. It flips the food pyramid on its head.
In a standard ketogenic diet, the typical breakdown is:
- High fat: roughly 70–80% of daily calories. Think avocado, nuts and seeds, olive oil, butter, cheese and cream.
- Moderate protein: roughly 20–25%. Meat, poultry, eggs, tofu and tempeh are common sources. Fish too, if you eat it.
- Very low carbohydrate: roughly 5–10%, usually under 50 g a day. Non-starchy veg like leafy greens, broccoli, cauliflower and zucchini do most of the work here.
Total carbs vs net carbs
In Australia, the carbohydrate figure on the label is the number we count. No extra sums.
If you’re looking at American packaging (and Australia imports a lot of American keto products, so this gets confusing), net carbs are worked out by subtracting fibre from total carbs. Check which one you’re looking at before you count anything.
Do you have to stay under 50 g to be in ketosis?
Ketosis means your body is using ketones for a bigger share of its fuel instead of glucose.
Where your personal line sits is a very individual answer with a lot of caveats. Under 50 g is the usual rule of thumb. People who are very active, with high energy needs, can often eat more carbs and stay in ketosis.
When I’m testing a theory, I go strict, 20 g or under. I know how my body reacts when I’m that strict, which helps me work out what’s going on. Most of the time I sit between 20 and 50 g.
Working out your macros
Macros are individual. Age, sex, activity level and a few other things change what your body needs to run well.
For what it’s worth, my maintenance macros work out to 141 g fat, 91 g protein and 45 g carbs, about 1,817 kcal (7,603 kJ). That’s mine. It isn’t a target and it isn’t a recommendation. If you want to work out your own, the keto macro calculator is a starting point, and how macros fuel our body explains what the numbers are actually doing.
What fat might be doing for pain
I love to hate the “fat makes you fat” conversation, so I’m leaving it alone and sticking to pain. Fat does several jobs in the body that are at least plausibly relevant to it. “Plausibly” is carrying a lot of weight in that sentence, so for each one I’ve said how strong the case actually is.
Omega-3s and inflammation
Omega-3 fats have the most research behind them when it comes to inflammation, mostly in inflammatory conditions like arthritis. Fatty fish is the usual source. Fish isn’t on my menu, so I use plant sources: flaxseed (I take a flaxseed supplement), chia seeds, hemp seeds and walnuts. These contain ALA, a plant omega-3. The body converts ALA into the longer-chain omega-3s quite inefficiently, so it isn’t a like-for-like swap for fish.
Whether any of this changes pain in CRPS, nobody knows yet. I also eat far less ultra-processed food on keto. That’s worth noticing, but I don’t have evidence that it changes pain on its own.
The endocannabinoid system
The endocannabinoid system is a signalling system found throughout the body. It involves cannabinoid receptors, the endocannabinoids your body makes itself and the enzymes that build and break them down. It’s involved in pain perception, mood, hunger, immune function and the stress response.
Endocannabinoids are fat-based, and your body needs dietary fats, including omega-3 and omega-6 fatty acids, to make them. That’s real biology. What I can’t tell you is that changing how much fat you eat changes how this system behaves in a way you’d feel. That link is still a hypothesis.
Fat-soluble vitamins
Vitamins A, D, E and K need fat to be absorbed. That’s well established, and it’s a good reason not to eat your salad dry. It isn’t evidence that keto helps pain.
Nerve health
Essential fatty acids like linoleic acid and ALA are part of how nerve cells are built and function. That’s textbook stuff. Whether eating more of them eases nerve pain in people is a different question, and as far as I can tell the evidence in humans is thin.
Staying full for longer
Fat and protein keep me full longer, and keto tends to fuel me for longer. That matters on the days when pain pushes my appetite away and I don’t have the capacity to cook more than once. It’s a practical benefit, not a pain mechanism. If you want more on the appetite side, Chasing pain: why eating matters covers it.
I’ve left weight out of this guide on purpose. It’s a much bigger and more loaded topic than a paragraph can hold.
What the research says about keto and pain management
If you’ve dug into the medical journals on CRPS, you’ll know the research is limited. Nutrition science and pain management is equally limited, so I’m working in a thin space here.
Chronic pain conditions overlap in some of their mechanisms, so findings from other pain conditions are worth watching. The obvious caveat is that they may not apply to CRPS. Everything below should be read that way.
A 2023 mouse study on how nerves use ketones
A 2023 study in mice looked at how a ketogenic diet reduces pain-like behaviour. It suggests that the body’s ability to burn ketones for fuel in sensory nerves matters, and that energy-sensitive potassium channels in nerve cells (ATP-gated potassium channels) are part of how that happens.
In plain language: ketones may change how sensory nerves handle energy, and that may change how they fire. It’s a mechanism worth knowing about. It is not proof that eating keto reduces pain in people.
Link: Mechanisms of Analgesia by a Ketogenic Diet
Rodent studies
Over the last few years there have been a handful of studies looking at ketogenic diets and pain behaviours in rodents. They report less touch-triggered pain (tactile or mechanical allodynia) and less spontaneous pain. Every one of them concludes that more research is needed, and I agree.
Mice aren’t people with CRPS. A diet that works in a cage can look very different in a kitchen with a pain flare, a flat appetite and no spare spoons.
The ones I’m following:
- Ruskin DN, Sturdevant IC, Wyss LS, Masino SA. Ketogenic diet effects on inflammatory allodynia and ongoing pain in rodents. Sci Rep. 2021 Jan 12;11(1):725. doi: 10.1038/s41598-020-80727-x. PMID: 33436956; PMCID: PMC7804255.
- Eto K, Ogata M, Toyooka Y, Hayashi T, Ishibashi H. Ketogenic Diet Alleviates Mechanical Allodynia in the Models of Inflammatory and Neuropathic Pain in Male Mice. Biol Pharm Bull. 2024;47(3):629-634. doi: 10.1248/bpb.b23-00732. PMID: 38494735.
- Enders J, Swanson MT, Ryals J, Wright DE. A ketogenic diet reduces mechanical allodynia and improves epidermal innervation in diabetic mice. Pain. 2022 Apr 1;163(4):682-689. doi: 10.1097/j.pain.0000000000002401. PMID: 34252910; PMCID: PMC10067134.
Where reality complicates it
Even if the mechanisms hold up, keto takes planning, shopping and cooking. That’s a big ask on a bad week. I dived in headfirst, and I think I made my life a lot harder than it needed to be in hindsight. That approach won’t work for everyone.
If you’re a fellow CRPS Warrior reading this, I’m not telling you to eat this way. I’m telling you what I looked into and what I found.
If you want to try keto: how I’d start now
- Browse first. Have a look at the meal plans and recipes. What’s already close to what you eat?
- Plan and prep a little. Even if you’re only cutting back on sugar or refined carbs to start with, a rough plan beats winging it.
- Swap, don’t rebuild. That might be a different marinade or sauce, or a keto-friendly pasta alternative. Cutting back on higher-carb, highly processed foods is a reasonable thing to try even if you never reach ketosis.
- Keep a food diary. Once you start swapping, note your energy, brain fog and pain. In my case it wasn’t always obvious. My energy and brain fog improved, and I noticed my pain less and less, until I ate something that set it off.
- Use the shortcuts. Frozen veg, pre-cut meat and jarred garlic all count. Convenience ingredients are accessibility tools, and you only get so many spoons.
Keto can change how some medications and conditions behave, so check with your GP or an Accredited Practising Dietitian before you make big changes.
For me, keto is one piece of a bigger plan that also includes treatment, pacing and a lot of trial and error. It sits alongside those things, not instead of them.
