Nick NorwitzMD PhD, Oxford-Harvard | Metabolic Health Educator | “Stay Curious”

MORE Saturated Fat and LOWER LDL Cholesterol?

16 Sept 2026 · 1 min

Watch on YouTube

1:00

In this YouTube segment, Nick Norwitz discusses a recent randomized controlled trial involving people with obesity who were assigned to a high‑fat ketogenic diet, a Mediterranean diet, or a low‑fat plant‑based diet. All groups achieved a similar weight loss of about 10% of body weight over six months. Despite the ketogenic diet containing roughly seven times more saturated fat and fifty times more dietary cholesterol than the plant‑based diet, both the keto and plant‑based groups lowered LDL cholesterol and ApoB to comparable extents. Moreover, the ketogenic group showed superior improvements in blood glucose control, liver fat reduction, inflammation markers, and insulin resistance. Norwitz emphasizes that, for individuals with obesity, reducing carbohydrate intake (cutting bread) may be more beneficial than limiting saturated fat (cutting butter). He notes additional nuance is provided in a linked free letter.

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These people ate 5 times more saturated fat and their LDL cholesterol went down. In a recent randomized controlled trial, people with obesity were randomized to eat a high-fat ketogenic diet, a Mediterranean diet, or a low-fat plant-based diet, and weight loss was controlled to about 10% of body weight over 6 months. And over that time, the low-fat plant-based diet and the high-fat ketogenic diet lowered LDL and ApoB by similar amounts, despite the keto diet containing 7 times as much saturated fat and 50 times as much cholesterol. Not only that though, the ketogenic diet group also had better improvements in blood sugar, liver fat, inflammation, and insulin resistance. So by many important measures, the keto diet beat the plant-based diet for liver and heart health, despite all the extra saturated fat. I do provide more nuance in the free letter I'm linking below, but the moral of the story is, for those with obesity, cut the bread, not the butter.