Should I eat a keto diet?

“Keto” diets are named for the process of forcing your body to use ketones as fuel instead of carbohydrates. Carbohydrates are the body’s first source for fuel that provides energy for daily life. Keto diets are purposefully low-carbohydrate and high-fat diets, and highly restrict consumption of carbohydrates (e.g., bread, pasta, rice and other grains, baked goods, potato products such as fries and chips, and high-carbohydrate fruits and vegetables). In the absence of carbohydrates, the body is forced to start breaking down fat for energy instead, which in the liver produces ketones.

In recent research presented at the American College of Cardiology’s Annual Meeting, people eating a low carb, high fat diet had significantly higher levels of both LDL cholesterol and apolipoprotein B (apoB), which is a more accurate determinant of the total amount of “bad” cholesterol in the bloodstream. After an average of 11.8 years of follow-up, people on the low carb, high fat diet had more than twice the risk of major cardiovascular events, such as blockages in the arteries that needed to be opened with stenting procedures, heart attack, stroke and peripheral arterial disease. In all, 9.8% of participants on a low carb, high fat diet experienced a new cardiac event, compared with only 4.3% of those on a standard diet.

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The study was only an observational trial, and only looked at what people reported they ate at the time of entry into the study. So it is certainly possible that they changed their diet over time.

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Despite those shortcomings, the analysis does represent yet another data point in the overall discussion of what makes a heart healthy diet. And there aren’t a lot of data points that show long term benefit from this type of diet.

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Iatan, I et al. “Association of a Low-carbohydrate High Fat (Ketogenic) diet with Plasma Lipid Levels and Cardiovascular Risk in a Population-based Cohort”, presented at ACC.23 Annual Meeting 3/5/23