This week's guest is Dave Feldman, who unusually for this podcast is not a doctor or a medical researcher, but actually a software engineer. For a long time, there has been concern that those on a very low carb or ketogenic diet are pushing their cholesterol to very high levels. This is something that Dave experienced personally, when he noticed the amount of his so called bad cholesterol -  the low density lipoprotein, known as LDL - shoot up on a keto diet. And when he found others reporting similar findings, he decided to set up an organisation called the Citizen Science Foundation to fund research to find out exactly what was happening in the particular case of  people like him - what he has labelled as lean mass hyper-responders - who are slim, metabolically healthy, but see their cholesterol levels rise substantially once they are on a ketogenic diet. Perhaps surprisingly, the early results from this work, suggest that this group -  contrary to what has been thought in the past - may not be endangering their health. At the very least what this research clearly demonstrates is the large gaps in our current understanding of the role of cholesterol in metabolic health. One illustration of this is an experiment carried out by one of Dave's colleagues, Nick Norwitz, who found that eating Oreo cookies while on a keto diet actually lowered his LDL cholesterol more than a statin, which I don’t think I need to add is not a recommended medical intervention! The host of the podcast, Liz Tucker is an award winning medical journalist and former BBC producer and director.  You can follow Liz on Twitter at https://twitter.com/lizctucker and read her Substack newsletter about the podcast at https://liztucker.substack.com If you would like to support this podcast you can do so via Patreon at https://www.patreon.com/WhatYourGPDoesntTellYou or via PayPal at https://www.whatyourgpdoesnttellyou.com/support/ What Your GP Doesn’t Tell You has been selected by Feedspot as one of the top 20 UK Medical Podcasts https://blog.feedspot.com/uk_medical_podcasts/