If people want to avoid vegetable and seed oils and get most of their fat from animal sources, that’s fine, but we know that this is not necessary. Thousands of people have had great success with low-carb and keto diets – whether it be for weight loss or reversing type 2 diabetes and many other conditions – for decades, with no emphasis on avoiding vegetable or seed oils.
How could this be? On the real food-based low-carb diet that we teach, the amount of processed food is very limited, so if there is a negative result from eating vegetable or seed oils, our patients are not getting many of these problematic oils so it may not be a concern in this context.
It’s also possible that the concern about vegetable and seed oils represents an issue in the food supply – that is to say, it matters population-wide, but for a given individual, the effect is small. I have to say that the human research on vegetable and seed oils (which are high in omega-6 fatty acids) that says they’re harmful for health is really not very impressive. It’s based on theoretical or blood tests and not on clinical outcomes. Many keto influencers include the avoidance of these oils at the same level of concern as avoiding carbohydrates, and this can be very confusing, making it difficult to follow a keto diet. The human clinical trial evidence for avoiding carbs is much stronger than the evidence to avoid seed oils.
Finally, all of the research about the oils has been done on people eating a Western standard diet – that is to say, a high-carb diet. Until recently there’s been no research on low-carb or keto diets and we don’t know if the effects of these oils are the same in the context of someone following a low-carb diet. There has never been a randomized controlled trial comparing two keto diets that differ only in their vegetable and seed oil content – that would be the study to do, and until this kind of direct comparison study is done, we don’t know that the results would be any better.
Remember, if vegetable and seed oils are a health concern, most people who adopt a low-carb keto diet will reduce their consumption of these oils automatically, because they will no longer be eating many of the foods that are big sources of it, like cookies, crackers, chips, and snack foods. The main sources of omega-6 fatty acids on a keto diet, where someone isn’t deliberately limiting it, would be condiments, salad dressings, mayonnaise, possibly nuts and seeds, and some people might use vegetable oil for cooking, like soybean or canola oil. Some extremely concerned people even avoid all chicken and pork because they’re higher in omega-6 fatty acids compared to red meat and seafood. They might avoid mass-produced chicken and pork and buy from a local farm because locally sourced animals do have a different fatty acid profile, but this extreme attitude toward food quality is not necessary. One of my patients lost 100 pounds just eating at a fast food restaurant, for example.
The main point is that thousands of people have had fantastic success with low-carb diets, whether for weight loss, reversing diabetes, heartburn, or PCOS, for decades with no emphasis on avoiding vegetable or seed oils. I see this in my clinic every day; it’s not just a theory or wishful thinking. If you want to avoid vegetable seed oils, you can. Is it possible there are some added benefits by doing it? Maybe, but in my experience, it isn’t necessary to focus on avoiding vegetables and seed oils to get great results from a low-carb keto diet.
Check out the full video here.