My Ketogenic Diet Journey with Bipolar Disorder

Have you ever wondered how a diet can improve, and even alleviate, chronic mental health issues? In this blog I want to share my journey with the ketogenic diet, which has made a huge positive difference to my symptoms and my life.

My name is Oliver Seligman. I'm the author of Befriending Bipolar: A Patient's Perspective, and I'm currently studying a Masters at Edinburgh University in the psychology of mental health. I've lived with bipolar disorder for 30 years, tried many treatments and medications, and so far the ketogenic diet has had the most profound effect on me.

How It Started

About a year and a half ago, Glasgow and Edinburgh University were looking for participants for the first pilot study of the ketogenic diet and its effects on people with bipolar. I was excited by the idea and volunteered. There were 26 participants who ate a modified ketogenic diet for six to eight weeks.

What Is the Modified Ketogenic Diet?

It's a very low-carb, high-fat, normal-protein diet. I had four meals a day, limited to 40 grams of carbohydrate. No sugar, no grains, no pasta. Around 180 grams of fat daily — olive oil, butter, cream — and a normal amount of protein. My mood, ketone levels, and blood sugar were regularly monitored for safety.

The Science Behind It

Most people run on the glucose pathway — we eat food, convert it to glucose, and our brain and body run on that. For some people this causes blood sugar spikes and crashes, and can contribute to insulin resistance. On the ketogenic pathway, the body converts fats into ketones instead. The theory is that for many people with bipolar, this leads to fewer mood swings and a much smoother ride emotionally.

I used a device called a Keto-Mojo to test my ketone and blood sugar levels at home, which helped me confirm whether I was truly in ketosis. Many people think they're doing keto but aren't eating low enough carbohydrates to actually achieve ketosis — even something like a packet of crisps can quickly spike blood sugar and knock you out of it.

My Experience

After a few days on the diet I experienced the "keto flu" — fatigue, mild congestion, and feeling a bit grumpy. It wasn't pleasant but it only lasted a few days. I've since found that taking electrolytes and drinking plenty of water prevents it entirely.

After about three weeks I started consistently reaching ketosis. The mental effect was remarkable — it was like my brain was taking a warm bath. I felt calmer, steadier, and more grounded. My mood improved significantly, the post-meal crashes disappeared, and my energy increased. It was genuinely hopeful.

An unexpected development was that my lithium side effects began worsening — more fatigue and headaches. I discovered this is actually quite common; many people on psychiatric medication find they need less of it on the keto diet. With my doctor's guidance I lowered my dose, and that's when I really started enjoying the benefits. Please note — never adjust medication without consulting your psychiatrist or doctor first.

The Challenges

It wasn't all easy. Being on a high dose of lithium affected my cognitive function, making it difficult to measure food and remember what I could and couldn't eat. I relied heavily on support from my wife and the study's nutritionist. Emotionally it was also tough — food had been a real comfort and reward for me, and giving up sugar and carbs was genuinely hard at times.

Going Back to Keto

When the study ended I gradually drifted back to eating normally. I didn't immediately relapse into depression, but after two to three months I noticed anxiety creeping back and some mornings I woke up feeling mildly low. That was my turning point — I knew I needed to return to keto, this time for myself.

The second time around was much easier. I avoided the keto flu with electrolytes, simplified to two or three meals a day, and stopped measuring food precisely since I'd learned what worked. I occasionally have a small slip — an apple or a few crisps — but as long as I don't go overboard it doesn't derail me.

The Biggest Result

The most significant outcome has been successfully lowering my lithium to just over half my original dose. The side effects previously were debilitating — migraines, long afternoon rest periods, cognitive difficulties, poor memory. Reducing my dose has transformed my quality of life. I'm starting to feel more, enjoy sensory pleasures again, and genuinely enjoy life in a way I couldn't before.

Does It Work for Everyone?

No — and I want to be honest about that. Current research suggests it works well for around a third of participants, works partially for another third, and doesn't help or makes things slightly worse for the remaining third. This is not a cure for bipolar disorder. But it has made a tremendous difference to me personally.

A Final Word

If you're considering the ketogenic diet, please do so with the support of your doctor and/or a qualified nutritionist. It can occasionally trigger mild hypomania when first starting. I am sharing my personal story only — I am not qualified to give medical advice.

That's my keto journey so far. I'll keep you updated, and I hope you found something useful here.

by Oliver Seligman (author of Befriending Bipolar: a patient's perspective.