Saturated Fats: Friend Or Foe On Keto?

The ketogenic diet is a high-fat, low-carb eating plan that has gained popularity in recent years. While it is often advertised as a weight-loss solution, it is a medical diet that comes with serious risks and should be followed under medical supervision. The keto diet derives up to 90% of its calories from fat, and it is important to distinguish between different types of fats to ensure the diet is followed healthily.

Saturated fats, typically found in meat and dairy products, have long been considered bad or unhealthy due to their association with raising cholesterol levels and the risk of heart disease. However, this notion has been challenged by recent studies, which suggest that the relationship between saturated fat and heart disease is more complicated and dependent on various factors, including individual responses, food sources, and the overall diet.

While some sources still recommend limiting saturated fat intake, others argue that it can be beneficial or neutral for health when consumed as part of a low-carb diet. The context of saturated fat consumption is crucial, and replacing saturated fat with refined carbohydrates or processed oils may increase cardiovascular risks.

Therefore, when following a keto diet, it is essential to choose healthy fat sources like avocados, olive oil, and nuts, while limiting saturated fat intake from bacon, butter, and certain types of cheese.

Saturated fat and LDL cholesterol

Saturated fats are fat molecules that are "saturated" with hydrogen molecules. They are typically solids at room temperature.

Saturated fats occur naturally in many foods, including meat and dairy products. Beef, lamb, some cuts of pork and poultry (with the skin on) contain saturated fats, as do butter, cream, and cheese made from whole or 2% milk. Coconut, coconut oil, and cocoa butter, as well as palm oil and palm kernel oil (often called tropical oils), are plant-based sources of saturated fats.

Consuming foods containing saturated fats causes the body to produce more low-density lipoprotein (LDL) cholesterol, also known as "bad" cholesterol. High levels of LDL cholesterol can increase the risk of heart disease and stroke.

The American Heart Association (AHA) recommends reducing saturated fat intake to less than 6% of total daily calories for those looking to lower their cholesterol levels. For someone consuming 2,000 calories per day, this equates to about 11 to 13 grams of saturated fat.

However, it is important to note that not all saturated fats are necessarily harmful. A recent in-depth meta-analysis found no link between dietary saturated fat intake and an increased risk of cardiovascular disease or type 2 diabetes. Additionally, moderate saturated fat consumption may offer some benefits, such as reducing levels of lipoprotein-a (Lp(a)), which is strongly correlated with heart disease risk, and raising HDL levels of heart-healthy "good" cholesterol.

When following a keto diet, it is crucial to focus on healthy fat sources, such as avocados, olive oil, and nuts, while limiting the intake of saturated fats found in foods like bacon, butter, and cheese.

Saturated fat and heart disease

Saturated fat has long been associated with heart disease, but this link is now being challenged. The idea that saturated fats cause heart disease, known as the 'diet-heart hypothesis', was introduced in the 1950s by physiologist Ancel Keys. Keys' hypothesis suggested that saturated fat and cholesterol caused heart disease by leading to fatty deposits of the type that clog arteries and cause heart attacks. This hypothesis became a foundation of public health policy, with most dietary guidelines worldwide recommending limits on saturated fat consumption.

However, recent re-evaluations of the evidence have led to a new consensus that saturated fats may not be as harmful as previously thought. More than 20 review papers by independent teams of scientists have concluded that saturated fats do not have a significant effect on cardiovascular outcomes, including heart attacks, strokes, or cardiovascular mortality. These reviews suggest that there is no consistent or adequate evidence to support continued recommendations to limit saturated fat intake.

For example, a 2010 analysis of clinical trial data found that while reducing saturated fat intake successfully lowered participants' cholesterol, it did not lead to reductions in cardiovascular or total mortality. Similarly, the Prospective Urban Rural Epidemiology (PURE) study, the largest-ever epidemiological cohort study, found no association between saturated fat intake and the risk of myocardial infarction or cardiovascular disease mortality. The PURE study also found a significant association between saturated fat intake and lower total mortality and a reduced risk of stroke.

Despite this growing body of evidence, national dietary guidelines have been slow to change their recommendations. The American Heart Association (AHA), for example, continues to recommend limiting saturated fat intake, citing the risk of raising "bad" LDL cholesterol and increasing the chance of heart disease and stroke.

So, while there is conflicting information about the direct link between saturated fat and heart disease, it is important to remember that saturated fats are just one piece of the puzzle when it comes to overall dietary health. Focusing on a balanced diet that includes a variety of fruits, vegetables, whole grains, lean meats, and healthy fats is crucial for maintaining a healthy weight and reducing the risk of heart disease and other health problems.

The different types of saturated fat

Saturated fats are not as unhealthy as once thought, but they can still raise your "bad" LDL cholesterol levels, increasing your risk of heart disease and stroke. They are typically solid at room temperature and are mostly found in animal-based foods, such as meat and full-fat dairy products. However, some plant-based foods like coconut oil, palm oil, and cocoa butter also contain saturated fats.

• Stearic Acid: Found in animal fat, coconut oil, cocoa butter, and palm kernel oil. It is considered relatively healthy as it may have a neutral effect on your blood lipid profile.
• Palmitic Acid: The most common saturated fatty acid, found in palm oil, red meat, and dairy. It raises LDL cholesterol levels but does not affect HDL cholesterol.
• Myristic Acid: Found in coconut oil, palm kernel oil, and certain other oils and fats. It significantly increases total cholesterol and LDL cholesterol.
• Lauric Acid: The longest of the medium-chain fatty acids, found in palm kernel oil and coconut oil. It raises total cholesterol, but this is largely due to an increase in HDL (good) cholesterol, which is beneficial.
• Caproic, Caprylic, and Capric Acid: These are medium-chain fatty acids, most commonly found in goat's milk. They may promote weight loss, increase insulin sensitivity, and reduce the risk of seizures.
• Short-chain fatty acids: These are produced when gut bacteria ferment fiber and are found in small amounts in dairy fat and certain fermented foods.

The benefits of saturated fat

Saturated fat has long been considered unhealthy, with the belief that it can lead to heart disease. However, this assumption has been challenged in recent years, with research finding no direct link between saturated fat intake and heart disease. In fact, saturated fat may offer several benefits, especially when consumed as part of a low-carb or keto diet. Here are some of the potential advantages of including saturated fat in your diet:

Improved Heart Health

While saturated fat has been associated with increased "bad" LDL cholesterol, recent studies suggest a more complex relationship. Saturated fat may also raise HDL, or "good" cholesterol, and reduce levels of lipoprotein-a (Lp(a)), a substance linked to a higher risk of heart disease. Additionally, certain types of saturated fat, such as medium-chain triglycerides (MCTs), have been linked to improved heart health by reducing the total-to-HDL cholesterol ratio.

Stable at High Temperatures

Saturated fats are typically more stable at high temperatures compared to unsaturated fats. This makes them ideal for cooking methods like roasting, baking, sautéing, grilling, or frying. Their stability helps prevent oxidation and the formation of toxic compounds, making them a healthier choice for high-heat cooking.

Improved Cholesterol Profile

Saturated fats, particularly long-chain saturated fatty acids, can optimize cholesterol levels. For most people, these fats increase HDL ("good") cholesterol and change LDL from small, dense particles (which are more likely to cause plaque buildup) to larger, more benign particles. This results in a more favourable cholesterol profile, potentially reducing the risk of heart disease.

Appetite Suppression and Weight Loss

Medium-chain fatty acids (MCFAs), a type of saturated fat, have been shown to reduce appetite and calorie consumption. This can help curb cravings and make weight loss easier. Additionally, MCFAs can increase ketone production and provide a more efficient fuel source for the body, further supporting weight loss.

Improved Brain Health and Cognitive Function

MCFAs, especially those found in MCT oil, have been linked to improved brain health and cognitive function. Studies suggest they may boost cognitive function in individuals with mild to moderate cognitive impairment and benefit those with neurological conditions such as Parkinson's disease, epilepsy, gliomas, and autism.

Blood Sugar Regulation

Saturated fats, particularly MCFAs, have been found to improve insulin sensitivity and help regulate blood sugar levels. This makes them potentially beneficial for diabetes prevention and treatment. Additionally, short-chain fatty acids (SCFAs) derived from gut bacteria fermentation may also positively impact blood sugar regulation.

Enhanced Immunity

MCFAs have been shown to possess antiviral and antibiotic properties, aiding the body in defending against various infections. This suggests that saturated fats may play a role in supporting and enhancing the immune system.

Improved Cell Membrane Stability

Saturated fats are less prone to oxidative damage than unsaturated fats, making them crucial components of cell membranes. They provide stability and help protect cells from damage.

While the benefits of saturated fat are notable, it is important to remember that context is crucial. The combination of saturated fat with refined carbohydrates and processed foods can increase the risk of heart disease, type 2 diabetes, and obesity. Therefore, saturated fat should be consumed as part of a well-formulated, healthy diet, such as a low-carb or keto diet, to maximize its potential benefits.

Sources of saturated fat

Saturated fats are typically solid at room temperature and are mostly derived from animal sources. They can also be found in some plant-based oils, such as coconut, palm, and palm kernel oils. These fats can increase your risk of heart disease and stroke by raising your cholesterol levels, specifically LDL cholesterol.

• Meat: Beef, lamb, pork, bacon, poultry (especially with skin), and cured meats like salami, chorizo, and pancetta.
• Dairy: Whole milk, butter, cheese, cream, crème fraîche, sour cream, and full-fat dairy products.
• Baked goods: Pastries, pies, cakes, doughnuts, cookies, and brownies.
• Processed snacks: Crackers, chips, and some savory snack mixes.
• Spreads: Mayonnaise, butter, lard, and other creamy spreads.
• Desserts: Ice cream, chocolate, chocolate spreads, and sweets.
• Oils: Coconut oil, palm oil, and other tropical oils.

Frequently asked questions