Why does the keto diet make me sick?
Before I start, I want to make 3 things clear:
I understand that when you first start doing keto, it’s common to experience what’s called the “keto flu.” I definitely had that. But I never, ever, got out of that phase.
I am not against the keto diet. Many people have benefited from it. Please don’t think I’m one of those people trying to label keto as harmful or evil. It’s not.
In fact, it can be incredibly helpful for some, including people with conditions like Chronic Fatigue Syndrome (CFS), Fibromyalgia, or POTS. I’ve even seen that some organizations that support people with CFS recommend keto with good results. Everyone’s body is different.
That said, if you have a dysregulated nervous system, I’d suggest taking your time with any dietary change., not just keto.
The keto diet is a high-fat, low-carbohydrate diet designed to put the body into a state of ketosis, where it burns fat for fuel instead of carbs. While transitioning, your body undergoes significant changes, and this can activate your sympathetic nervous system (fight or flight system). That’s what people refer to as the “keto flu.”
In 2019, I decided to try the keto diet. I wouldn’t have considered myself “chronically ill” at the time, although I was starting to notice some things in my body that felt off. I was still generally functional. Emotionally, I was also healing from a very broken heart, and like many, I wanted to feel better, get fit, and regain a sense of control. Several of my friends were doing keto and having great results, my doctor at the time thought it would be good as well since I needed to lose 50 pounds and was having issues with my energy levels. so I figured, why not?
I did my research, got the doc involved, and I bought what I needed. I honestly felt rather prepared. Friends and the doctor warned me about the keto flu and gave lots of suggestions. Things like pickle juice, electrolyte powders, etc. to help manage it. So, I felt ready.
I got the keto flu, but I never got past it. It was strange. I’ve tried other diets before, and my body usually adjusts within a few days or a week. But this was different. I kept waiting for the surge of energy everyone talked about. My friends kept telling me that their workouts felt amazing and your brain lights up. That never happened for me.
After two months of pushing through, what finally made me stop was the burning and prickling in my legs and feet. It felt like nerve pain, almost like neuropathy. The doctor had no idea why I was struggling with it. Looking back, I still can’t believe I forced my body to keep going for that long.
Looking back, I now see that entering ketosis interacted with my nervous system in a way that amplified my underlying dysregulation. It didn’t cause my condition, but it exposed it. These were the early signs. As much as it “didn’t work” it was trying to tell me something.
Keto seemed to increase sympathetic nervous system activity which was pushing my body into a sustained fight-or-flight state. It destabilized me further. The diet revealed vulnerabilities that were already there, simmering beneath the surface.
It’s also worth noting something I’ve observed in myself: when I start anything new, whether a protocol, supplement, or even a basic vitamin, my system tends to react unfavorably. I’ve come to understand this as a pattern linked to chronic freeze response. There’s an exaggerated initial reaction, followed by a quick plateau, and eventually a full drop-off in responsiveness. It’s as if the system burns through its capacity early, then shuts down under overstimulation. With the Keto diet, there was never an official drop off period. It was purely initial reaction oriented.
We are all different. What didn’t work for me may work great for someone else.
#chronicillness #functionalfreeze #chronicfatigue #potssyndrome #fibromyalgia
Starting a keto diet can bring significant changes to your body's metabolism, but for some with a dysregulated nervous system, these changes may trigger unexpected and persistent symptoms. The onset of the "keto flu"—characterized by fatigue, dizziness, brain fog, and even neuropathic pain—is often a sign that your sympathetic nervous system (the body's fight-or-flight mode) is highly activated. While many experience keto flu temporarily, lasting symptoms can indicate underlying vulnerabilities. Individuals with conditions such as Chronic Fatigue Syndrome (CFS), fibromyalgia, or Postural Orthostatic Tachycardia Syndrome (POTS) may find that their nervous system is already in a fragile state. Ketosis might amplify this stress response, leading to sustained sympathetic activation that keeps the body in an overstimulated, fight-or-flight condition. Symptoms like burning and prickling nerve pain, especially in the lower limbs, can be a sign of this interaction between ketosis and nerve function. This phenomenon can resemble neuropathy but may stem from nervous system dysregulation rather than typical nerve damage. The experience of an exaggerated initial reaction followed by an absence of the usual energy surge from keto suggests that your system’s capacity to adapt is overwhelmed. This pattern, sometimes called a chronic freeze response, means your body reacts to new inputs with heightened sensitivity and then shuts down responsiveness, limiting the benefits from the diet. It’s important to approach any dietary change gradually, especially when you suspect nervous system dysregulation. Tools like electrolyte supplements and careful pacing might ease symptoms but may not fully resolve underlying nervous challenges. Ultimately, everyone's body reacts differently to keto. If you find yourself stuck in an extended keto flu or experiencing nerve pain, it may be wise to consult with healthcare practitioners familiar with autonomic nervous system disorders and consider personalized modifications to your approach. Listening carefully to your body's signals and moving slowly with dietary changes can help prevent exacerbating underlying issues and support your journey toward better health.