Fats Are Needed for Survival
There has been much controversy in recent years surrounding the benefits of dietary fat and the therapeutic applications of high fat diets. I must say this: fats, and specifically polyunsaturated fatty acids, are essential for us humans. What this means is that they are key for human survival and the only way to obtain them is through our diet. Amino acids, the building blocks of proteins, are too divided into essential and non-essential. Many of them are synthesized by the body, but others need to be obtained through diet. In contrast, there is no such thing as essential carbohydrates.(1)
It is true that carbohydrates are the quick-access fuel for the body and brain, but in their absence, we have the built-in mechanisms to shuttle fats and protein into the Krebs cycle to make energy -- a process called gluconeogenesis. (2), (3) This process occurs continuously in the liver, kidneys and to some extend, in the intestines but is particularly active during times of food depravation and glucose shortage. Fortunately, over the course of human evolution, our body has become well equipped to handle such circumstances. In fact, our metabolism operates more efficiently when the body is able to use fat (stable, long-term energy source) instead of glucose (quick, insulin-dependent energy source) on a consistent basis. Think about it for a minute: hunter-gatherers did not have refrigerators and the availability of food we enjoy today. They ate whenever they could catch a wild animal or fish (high in protein and healthy fat), and their carbohydrate intake consisted of berries, grasses, roots and tubers, which are all low in sugars and super high in fiber. Having to sometimes fast for prolonged periods of time, their metabolism adapted to allow them to tap into their body's fat stores in order to survive. The ability to switch from sugar burning to fat burning metabolism is encoded in our DNA.
Improve Your Metabolic Function
In the fat adapted state, you lose cravings for carbs, feel full faster at mealtimes, and stay feeling full longer, which then inspires you to eat less and still have good energy and stamina.(4) The key to becoming fat adapted and tap into your stored energy reserves is to practice periodic or intermittent fasting on a regular basis and to increase your healthy fat intake (50-80% of total daily calories) while lowering dietary carbohydrates (less than 20%, and in strict Keto diets, to even less than 10% of total calories).(5)
To be clear, you don't necessarily have to adhere to a strict ketogenic diet to become fat adapted; the ideal ratio of carbs, protein, and fat, or the ratio at which you become fat adapted, may vary depending on your individual metabolic state.(6)
Here is an example of a high-fat diet dairy where carbohydrate intake is kept below 50g per day, or in this case at about 10% of daily calories while fats are around 70% of daily calories. This is in line with a stricter version of the ketogenic diet. Keep in mind that the Keto diet is not one-size-fits-all and there are several variations based on each person's unique nutrient needs and metabolic profile, which have to be individually assessed.
Benefits of High (Anti-Inflammatory) Fat Diets
Fat is indeed an important part of the human diet. It is needed to build cell membranes as well as the myeline sheaths helping to protect our nerves. It is also important for blood clotting, muscle movement, hormone synthesis, and proper immune system function. Fat also facilitates the absorption of important antioxidant nutrients like vitamins A, E, D and K.
In my clinical practice, I have found that high-fat diets (50-70% of total daily calories) work well for improving various markers of health including metabolic and cognitive function. High fat/low carb diets (in contrast, high fat/high carb is a recipe for metabolic disaster) help to improve insulin sensitivity, lipid profiles (specifically lowering triglycerides and increasing HDL cholesterol), as well as mitochondrial and cognitive function.(7)
There is also plenty of research on the neuroprotective effects of Ketogenic (high fat) diets and their therapeutic use in debilitating conditions like epilepsy, cognitive decline, dementia, and Alzheimer’s disease.(8),(9) Of course, the quality of fat matters; eating burgers and cheese or highly processed and hydrogenated oils is not the same as eating cold water fish, nuts, seeds, and avocados.
The Quality and Source of Fat Matters
What matters most when it comes to dietary fat is the source and quality and not so much the amount, according to Dr. Mark Hyman, Director at the Cleveland Clinic Center for Functional Medicine and author of the best selling book Eat Fat, Get Thin: Why the Fat We Eat Is the Key to Sustained Weight Loss and Vibrant Health. (10) Trans-fats and refined vegetable oils promote abnormal cholesterol profiles, says Dr. Hyman, whereas, omega-3 oils from fish and monounsaturated fats found in nuts, avocados and olive oil can actually improve the type and quantity of your cholesterol. (11)
Interestingly, according to another article by Dr. Hyman, researchers have also found that when people consume more saturated fat—especially from healthy sources like coconut oil—their “good” HDL cholesterol increases and their “bad” LDL decreases.(12) His conclusion: "saturated fat in foods like extra virgin coconut butter fuels your mitochondria, provides anti-inflammatory benefits, and could even improve your cholesterol numbers."
Unfortunately, the standard American diet, appropriately abbreviated SAD, provides very little of the healthy, anti-inflammatory fats and is very high in pro-inflammatory omega-6 fats thanks to our excessive use of cheap, processed oils like soybean, corn, sunflower, and canola.(13) Omega 6's are not all bad though, in fact they too are essential and we need some in the diet but the source is important. Omega-6 fats help with brain function, muscle growth, and hormone production, but they also cause inflammation, and compete with omega 3's in the body. (14)
Optimize Your Omega 6:Omega 3 Fat Intake
Research shows that an optimal ratio of omega-3 to omega-6 is key when it comes to good health and longevity.(15) Many nutrition experts suggest that the ratio of omega-3 to omega-6 should be around 1:3 or 1:4. Human beings evolved on a diet with a ratio of approximately 1, whereas in our modern diet today the ratio is 1:15 - 1:25.(13) Needless to say, most of us are deficient in omega-3's and consume excessive amounts of omega-6's compared with the diet on which humans evolved. We now know that a high omega-6 to omega-3 ratio is associated with increased levels of inflammation and a high risk for a variety of chronic diseases including cardiovascular disease, autoimmune disorders, metabolic syndrome, and even cancer.(16)
The anti-inflammatory omega-3 fats include ALA (alpha-linolenic acid), a short-chain fatty acid mostly found in plant foods like flax and chia seeds. Alpha-linolenic acid can convert to DHA, but the process is not particularly efficient in the human body. Studies in recent years have indicated a very limited conversion efficiency from dietary ALA to DHA, ranging from 0 to 8% on average.(17)
The other two omega-3 fats are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) - two long chain fatty acids obtained mostly from animal sources. They are integral part of cell membranes and help to fight inflammation. DHA is now widely recognized as the physiologically-essential nutrient in the brain for normal functioning of neural tissue (including cognitive performance, learning ability, and memory) and in the retina of the eye for visual acuity. (11),(17) Additionally, according to several epidemiological studies, consistently adequate intake of DHA/EPA (650 mg or more) through supplementation or regular fish consumption, has been shown to significantly decrease the risk for cardiovascular disease and fatal cardiac events.(17)
The best food sources are wild caught salmon, sardines, other cold water (low mercury) fish, raw oysters, grass-fed beef, algae, Brussels sprouts, cauliflower, and walnuts.
While I certainly think that fat is and should be an important part of our diet, there are fats that need to be completely avoided and namely industrial-made trans fats (hydrogenated or partially-hydrogenated oils) which are produced by adding hydrogen to vegetable oil converting the liquid into solid fat at room temperature. This process is called hydrogenation. (18)
Eating foods high in trans fats has been shown to increase bad cholesterol levels as well as the risk for heart disease, stroke, diabetes as well as other chronic diseases. Thankfully, the FDA took measures to remove trans fats from food products in the US in 2015 and as of June, 2018, manufacturers can no longer add partially hydrogenated/industrial-made oils to food. (18)
A High Fat Diet Is Not One-Size-Fits-All
Whether or not you decide to try a high-fat or ketogenic diet, which as I mentioned earlier is a highly individualized approach and should be monitored by a nutrition professional, you will certainly benefit from adding more heart- and brain-healthy, anti-inflammatory fats to your diet. Start by gradually increasing the intake of the Omega 3's and other unprocessed plant-based fats, while lowering the amount of carbohydrates you consume, especially the refined flour products, pastries, and added sugars.
Below you will find one of my favorite recipes (a staple in my house) for Keto friendly bread made with no grain flour and only raw, unprocessed nuts, seeds, fiber and healthy oils. It is absolutely delicious, so give it a try and be sure to leave your feedback and comments below. Enjoy!
Be Well ♥
Delicious Keto Bread Recipe
Macronutrient ratio in grams per serving: Net Carbs (2g), Protein (6.1g), Healthy Fats (18g)
Servings: 10-12 slices
1 cup raw, hulled sunflower seeds
1 cup raw nuts (hazelnuts, almonds, Brazil nuts or walnuts)
1⁄4 cup raw pumpkin seeds
1/4 cup raw flax seeds
2 Tbsp chia seeds
1/4 cup of melted coconut or extra virgin olive oil
2 cups water
Sea salt to taste
Blend all nuts and seeds (except for chia) in a blender or food processor to make flour.
Add psyllium husk powder, chia seeds, and sea salt and mix well.
Stir in the melted coconut or olive oil and water and mix all ingredients together to make sticky dough. You can get your hands dirty here!
Place the dough in a silicon loaf pan. Smooth out the top with the back of a spoon or spatula. Cover pan with a clean kitchen towel and let sit out on the counter for 2 hours, all day, or overnight. To ensure the dough is ready, it should retain its shape even when you pull the sides of the loaf pan away from it.
Bake in the oven at 350°F / 175°C for 30-45 min.
Store bread in a tightly sealed container for up to five days. Freezes well too, but be sure to slice it up before freezing. #Ketogenicdiet #Highfatdiets #Antiinflammatoryfats #NutritionistBoston #EatFat #Fatadaptation #Ketorecipes #Ketobread #EatFatGetThin