My LDL cholesterol went up on a ketogenic diet. Is that a problem?

Stephen D. PhinneyMD, PhD · physician-scientist; co-founder and former Chief Medical Officer, Virta Health

Not on its own. Get particle number and ApoB, and read the rise against the whole risk panel before you act on it.

What it rests onIn his company's one-year trial (Bhanpuri et al. 2018, reported in the Virta post) calculated LDL cholesterol rose slightly while total LDL particle number and ApoB were unchanged and the distribution shifted toward larger particles, alongside a large fall in triglycerides, a rise in HDL and a ten-year ASCVD risk score change of -11.9 percent. His mechanical point is that standard-panel LDL is calculated rather than measured, and a large change in triglycerides skews the calculation, so on this diet the calculated number is least trustworthy exactly when it moves. The evidence is his own company's trial: Virta Health sponsored it, it tested Virta's programme, and he is a founder and employee offered stock options.

Christopher D. GardnerPhD · nutrition scientist, Stanford Prevention Research Center

Treat it as a real cost of the diet to weigh against its benefits. Get your lipids checked and expect LDL to rise.

What it rests onThe Keto-Med randomized crossover trial he led: LDL cholesterol rose about 10 percent on the ketogenic arm and fell about 5 percent on the Mediterranean-plus arm, while triglycerides fell 16 percent against 5 percent. He attributes the pattern partly to what the ketogenic arm removes, since dropping legumes, fruit and whole intact grains lowered fibre and several nutrient intakes. Read the whole abstract before characterising him: HbA1c did not differ between the two diets and improved from baseline on both, and he grants the triglyceride advantage. He is not arguing the ketogenic diet failed; he is arguing it carries 'potential untoward risks from elevated LDL cholesterol and lower nutrient intakes' and was 'less sustainable'. No commercial relationship found.