Winter is coming in the northern hemisphere and with it the ubiquitous flu season. Yes, even those on LIHF are not immune to the dreaded flu bug but there is plenty of good news for LIHF practitioners, both in terms of alleviated symptoms and speed of recovery, even if you have to fall back on some extra carbs to do so. 

My Findings

What I am about to tell you here is based entirely on my own personal experience and the anecdotal evidence of others I know of, principally friends and family also on LIHF. I haven’t read or even heard of anything else directly relating to viral infection, in particular the flu virus and its effects when on an LIHF (low inflammation) diet but I feel this is now worth writing about and sharing with others.

The difference between my flu symptoms before and after LIHF are remarkable. Prior to LIHF, influenza almost always entailed a period in bed, covered in extra blankets, shivering, running an elevated temperature and completely unable to function in any other capacity.  Since LIHF however, flu symptoms are markedly reduced. At first I thought this was an anomaly or just my imagination but after 3 years of LIHF and several bouts of influenza, it can no longer be ignored. Make of this what you will but for me the evidence is clear: the effects/ symptoms of the flu virus when on LIHF are SEVERELY reduced, to the point of almost being non-existent!

Symptoms & extra use of Carbohydrates

The obvious question: If the symptoms are so mild these days, how do I know I am actually getting the flu? The answer is because I have a four-year-old daughter in day care who drags home EVERY conceivable virus currently making the rounds. Once she is infected, about a week or so later, I usually get the first symptoms that anyone gets with the flu i.e. tickly/ sore throat and mild shivers, a sure sign that you’ve been infected. However, this is where the similarities between before and after LIHF end. Nowadays on LIHF, rather than a rapid deterioration, this is about as bad as it gets. The only other major difference is that I start to feel lousy due to a lack of energy similar to a blood sugar crash that one experiences on a high carb diet, shortly followed by major cravings for sugary/ sweet things. Never at any other time do I have such strong cravings for sweet things. If I simply ignore it and carry on with my usual low carb diet, whilst I never feel “bed-ridden bad” in any way, neither do I actually feel that I am firing on all cylinders either. I have learned not to fight these feelings because you can’t and the only solution is to go out and get myself a massive “sugar hit” in the form of sweets, pastries or whatever it takes to feel revitalized. As soon as I do this, I feel fine again. If I get a repeat crash, I just do the same again, and so on until I start feeling better again. Recovery is very quick, max one week with extremely mild flu symptoms, if any at all and I am able to function almost as normal throughout.

The Science

So what exactly is going on here? Again, the following explanation is my theory only  but it is entirely consistent with the science of inflammation.  As I explained in this post, inflammation has many causes, one of the major ones being disease. A viral infection will increase levels of inflammation and hence also block ketosis to some extent. For the keto-adapted individual whose diet is primarily based on fat this isn’t good news and blood sugar levels will start to fall in just the same way as someone on a high carb diet who hasn’t eaten for a while, or has expended a lot of energy during exercise. So the only solution to increase blood sugar in this state is to take on some simple carbs until you start to feel better again. There is of course a small penalty in weight gain but I have found that in practice this is negligible, say 1kg max, and soon disappears again once clear of the virus and full ketosis returns. Symptoms remain mild/ reduced because overall levels of inflammation remain low, despite the short term increase in carb intake.

In Practice

This is how I proceed as soon as I get those first flu symptoms:

• Maintain a normal LIHF diet until you start to feel weak due to low blood sugar.
• If you get an overwhelming urge to eat sweet and sugary things, don’t fight it! Pile into the carbs until your blood sugar levels stabilize and you start to feel better again. Repeat as often as necessary without necessarily counting your daily carb intake. If it takes 100g/day of carbs or more then so be it!
• Get plenty of rest but otherwise carry on as normal. Avoid exercise unless you feel like it.
• Expect some weight gain but also expect to lose it all very quickly again once you’ve fully recovered.
• You will know when you have recovered because sugar/ sweet cravings will disappear and cravings for fatty food will gradually return.
• Keep up your daily supplements, in particular zinc which helps to fight disease.