Ask HN: Is there any evidence in favor of or against ketogenic diet?

1. It depends a lot on individual factors.

2. What we know is limited.

3. Caloric restriction seems helpful, regardless of what you actually eat.

I haven't really looked at keto. What I can tell you is that different fats have different chemical composition and this impacts how the body reacts to them, especially if you have specific problems.

I have no plans to ever get all that knowledgeable about keto. I don't think it actually makes sense and I suspect its positive reputation is probably rooted in benefits from confounding factors that haven't been identified, such as inadvertently eliminating allergens for some people. If you stop eating things that are actively making you low grade sick, you will feel better, possibly dramatically so, and it almost doesn't matter what you actually are eating, so long as it is less harmful than what you were consuming.

I'm no expert, either. I've read some of the relevant literature when able, and I've experimented extensively with food and supplements. I also collect anecdotal evidence for the success and failure of different dietary regimes. I think it's especially instructive when your own chosen regime fails for other people. Caution is always warranted.

If you ask a toxicologist whether or not something can kill you, the reply will come swiftly: "How much?" Given the number of people that die each year from water toxicity, we clearly lack intuition regarding the answer. When it comes to fat (saturated fat, in particular), there clearly must be some upper limit before pathologies arise, but the question actually being debated is, "How little saturated fat should we consume?" Similar questions have been posed about cortisol and inflammation, two "obviously bad" things that, as it happens, we cannot do without.

From this standpoint, such debates are largely ideological, as contradictory evidence, discovered in earnest, for opposing viewpoints implies both must be wrong in some fundamental way. Scientists generally recognize this; enthusiasts and journalists, less so. This in no way means proponents are wrong about their observations. Rather, it means their conclusions--that is, the model through which they view their results--are somehow incomplete. This is where new science can shed the most light.

All of this is a long-winded way of saying I have no idea how to reconcile even the data I have seen because there's so much data I haven't read or don't understand. Besides, even experts are weary to give medical advice. And just because my blood work on a ketogenic diet looks fine, that doesn't mean your family history won't affect your own results on the same diet.

If you don't trust your physician to keep up on the latest nutritional science (Why would they?), you can at least work with them to monitor lipid panels while experimenting with your diet. Regular blood work every couple years can also alert you to drastic changes you might not otherwise be aware of. Just be sure to request complete copies of the data for your own records. Otherwise, you may only receive a list of notable results.

Best of luck to you.