Is The Keto Diet Healthy? (Saturated Fats) | Jason Fung

Summary

The video script challenges the conventional belief that a high intake of saturated fat, as seen in the ketogenic diet, leads to heart disease. It reviews recent evidence, including a state-of-the-art article from the American College of Cardiology, suggesting that natural saturated fats from whole foods may not increase the risk of heart disease, diabetes, or stroke. Instead, it posits that dietary carbohydrates, through de novo lipogenesis, could be more detrimental. The script also highlights historical dietary guidelines, the French paradox, and large-scale studies that indicate a reevaluation of saturated fat's role in heart health.

Takeaways

• 🫀 The keto diet, which includes high levels of total and saturated fat, is not unhealthy and does not clog arteries or cause heart disease.
• 📚 Recent scientific evidence shows that saturated fat does not cause heart disease, contrary to what was believed since the 1960s.
• 🔬 A state-of-the-art review by top cardiologists in the Journal of the American College of Cardiology concluded that there is no benefit in reducing saturated fat intake.
• 🥩 Whole foods like full-fat dairy, red meat, and dark chocolate, which contain saturated fats, do not increase the risk of heart disease, diabetes, or stroke.
• 🍞 Dietary recommendations should focus on whole foods rather than specific nutrients, as the overall food matrix is more important for health.
• 🇺🇸 The 1977 dietary guidelines recommending low fat intake were based on weak evidence and cherry-picked data.
• 🥄 Replacing saturated fats with unsaturated fats or vegetable oils, as was recommended in the past, led to the consumption of trans fats, which are harmful to heart health.
• 🍫 Studies have shown that there is no correlation between total fat intake and the risk of heart disease, and in some cases, higher fat intake is protective.
• 🧀 Full-fat dairy has been linked to a lower risk of diabetes and does not increase the risk of heart disease.
• 🫀 A high carbohydrate intake is more strongly associated with higher levels of saturated fat in the blood and an increased risk of heart disease than dietary fat intake.

Q & A

Is the keto diet considered unhealthy due to its high fat content?

The script suggests that the keto diet, which is high in total fat and saturated fat, is not necessarily unhealthy. Recent scientific evidence and cardiologists' consensus indicate that saturated fat does not cause heart disease, and people who consume more fat may actually be protected against stroke.

What was the conclusion of the review published in the Journal of the American College of Cardiology in August 2020?

The review concluded that reducing saturated fat intake does not have beneficial effects on heart disease. Instead, it found that consuming more fat could be protective against stroke. The top cardiologists recommended making dietary recommendations based on whole foods rather than specific nutrients.

What does the script say about the sources of most saturated fat in our diets?

Most saturated fat comes from whole fat dairy, red meat, and dark chocolate, which are complex food matrices. The script emphasizes that these natural fats do not increase the risk of heart disease, diabetes, or stroke.

What was the initial recommendation in the 1977 U.S. dietary guidelines?

The 1977 U.S. dietary guidelines recommended avoiding too much fat, saturated fat, and cholesterol. However, the script points out that this advice was based on weak evidence and a few observations from an influential researcher.

Why did the low-fat diet become popular, and what was its intended health benefit?

The low-fat diet became popular because it was believed to reduce heart disease by lowering LDL cholesterol levels. However, newer research shows that it's not as simple as that, and the diet may not necessarily lead to a decrease in heart disease risk.

How does the body produce saturated fat in the blood, and what dietary factors are associated with it?

The body produces saturated fat in the blood through a process called de novo lipogenesis, where excess carbohydrates are turned into fats for storage by the liver. The script indicates that the amount of saturated fat in the blood is more related to carbohydrate intake than dietary saturated fat.

What is the 'French Paradox' mentioned in the script, and how does it relate to saturated fat consumption?

The 'French Paradox' refers to the observation that despite consuming a diet high in saturated fat, such as whole fat dairy, the French had less heart disease than other countries. The script suggests that the saturated fat in natural foods does not cause heart disease, thus explaining the paradox.

What did the largest epidemiologic study published in The Lancet in 2017 find regarding saturated fat and heart disease?

The study found that as saturated fat intake increased, the risk of heart disease tended to decrease. It also suggested that consuming a high percentage of carbohydrates in the diet might increase the risk of heart disease.

What is the script's stance on the consumption of whole fat dairy and its relation to diabetes?

The script suggests that contrary to previous recommendations to consume low-fat dairy, whole fat dairy does not lead to an increased risk of heart disease and could protect against diabetes, which is a risk factor for heart disease.

Why have some physicians started to favor the ketogenic diet?

Some physicians favor the ketogenic diet because it includes natural fats and saturated fats, which recent evidence suggests may not lead to heart disease and could be protective against stroke. Additionally, it has been linked to a reduced risk of diabetes.