The Importance of Dietary Animal Fat


Animal fat was evolutionary man’s major source of energy. Ancient humans lived primarily on eggs, fish, animals, and other living creatures. Dietary sources of glucose were minimal. Human biochemistry is in agreement with these paleolithic findings.

In contrast, the modern human uses two classes of food to provide energy for life functions; carbohydrates yield glucose, and fats supply fatty acids. Despite the fact that glucose serves as the usual and ready source of energy for the body, long-term sustained energy depends on fatty acids. Fatty acids are a much more efficient fuel than glucose. They contain twice the energy per unit weight and they are stored more compactly. Under normal conditions, the body uses both fuels alternately depending on time from last meal.

As a rule, glucose is plentiful after a meal, but it becomes in short supply several hours later before the next mealtime. Glucose is used preferentially as long as the supply of glucose is adequate. When the supply becomes low, the body switches over to using fatty acids because glucose reserves must be preserved to maintain normal blood glucose levels.

When carbohydrate foods are reduced or eliminated from the diet, the body must turn to fatty acids for energy. This presents a major difficulty for people who have been schooled in the official government recommendations to eliminate dietary fat; particularly animal fat because they say animal fats will make you ill. There is no scientific evidence that animal fats cause heart disease or any other chronic illness. On the contrary, there are considerable scientific data that vegetable fats contain omega-6 fatty acids that are harmful when consumed in excess2. Therefore, animal fats are the preferred dietary fat.

A person consuming a low-carbohydrate diet who also restricts dietary fat is begging for trouble. Dietary fat will be used first. Then, if fat is available in body fat stores, it will be mobilized for energy. This is the reason for the weight loss that occurs with low-carbohydrate diets. If no excess body fat is available, the body will search for glucose. It is at this point that a paucity of dietary fat becomes a potential health problem. The body makes new glucose from amino acids that are classed as nonessential, i.e. amino acids that the body can make for itself.

The process whereby the body makes new glucose is called gluconeogenesis. If the body is called upon to engage in gluconeogenesis to any great extent or duration, it can seriously disrupt protein metabolism. In order to obtain sufficient glucose, the body depletes circulating proteins and cannibalizes muscle tissue. Pictures of holocaust victims show the tragic result. Small deficiencies of dietary fat would probably not cause detectable gluconeogenesis, except for people who follow their blood glucose levels with a monitor. Anyone on a diabetes recovery program should be aware of this and take steps to increase fat intake. Too little dietary fat can be dangerous; too much dietary fat is not a problem providing it does not exceed the bounds of satiety(3, p. 91). When it does, it may interfere with the benefit of weight loss promoted by a low-carbohydrate intake.

How much fat should a person on a low-carbohydrate diet consume?(4) This is a highly individual matter. The idea is to provide enough energy from fat to replace the energy no longer available from dietary carbohydrates. Dietary fat should be increased when one is hungry. Dietary fat should also be increased if there is a continuous feeling of lack of energy or fatigue. Finally, dietary fat should be increased if the blood glucose monitor shows an increase in blood glucose greater than a usual reading or if fasting blood glucose readings remain above normal.

The easiest way is to add fat is with patties of butter or portions of a high milk fat product like cream cheese. The amount included in the diet should be sufficient to relieve the symptoms. It can do no harm to eat more fat than needed.


  1. Ottoboni A&F with Bob. Recovery from Type II Diabetes: A True Story. Fernley, NV: Vincente Books, Kindle edition, 2013, in press.
  2. Ottoboni A, Ottoboni F. The Modern Nutritional Diseases and How to Prevent Them. Fernley, NV: Vincente Books, 2013.
  3. Eades MR, Eades MD. Protein Power, Paperback Edition. New York, NY: Bantam Books, 1999.

18 Responses to “The Importance of Dietary Animal Fat”

  1. Thanks for the post, great summary.

    A question I still have though is whether (and to what degree) gluconeogenesis still occurs if someone DOES have body fat to lose. In the section warning about restricting dietary fat, you explain fueling in this order: 1) Dietary fat. 2) Body fat. 3) Aminos->muscle etc. Would this not suggest then the best low-carb diet for body fat burning is indeed low-dietary-fat (essentially meaning only dietary protein)? I’ve noticed a lot of low-carb proponents are pushing lower protein, higher fat diets these days even before getting to a maintenance phase (where everything you explained makes perfect sense.) Is that approach misguided or what are some other factors at play?

    • Alice and Fred Ottoboni

      Many thanks, Kjulian, for an extremely important question that is worthy of further discussion.

      One important point for a starter is that the human body is in what is referred to as a state of dynamic equilibrium – constant movement striving for constant balance with all sorts of reactions going on at once. So it is most likely that a few gluconeogenetic reactions making new glucose are taking place somewhere in the body at any one time. The goal in a low-carb diet is to keep the supply of fat available for energy that is sufficient to prevent the need for a large amount of new glucose.

      Your logic is correct, if one has a great amount of body fat to burn it would seem reasonable to cut down on dietary fat and use only body fat for energy. But the body does not always go by logic. It takes time to mobilize body fat and convert it to energy. Meanwhile, the body needs the more quickly available dietary fat to provide energy. The body will use both sources at the same time, and if both are insufficient, it will then make glucose. Thus, if weight loss is the goal, do not box yourself in with a low-fat plan, but keep it flexible; keep the proper macronutrient balance and reduce total calories. If you do not lose weight, then cut back slowly on the nonessential fatty acids until weight loss resumes.

      Remember, all fat is not equal. Be sure to have appropriate amounts of the essential fatty acids and the smaller chain saturated fatty acids. Remember, if the goal is weight loss, body fat will provide plenty of long chain saturated fatty acids.

      Finally, protein intake should be your first consideration. It is generally accepted that dietary protein intake should be 30% of daily calories based on lean body mass.

      • Thanks for the response. I hadn’t considered the efficiency of mobilizing body fat– that explanation makes a lot of sense to me. Keep up the great work…

  2. Lowen Gartner

    Why “The Importance of Dietary Animal Fat” rather than “The Importance of Dietary Fat”? What if one ate low carb high fat and all fat was derived from plant sources (or most along with a DHA supplement)?

    • Leaf Eating Carnivore

      Plant fats – too many omega-6’s. See paragraph 4, reference 2.

    • Alice and Fred Ottoboni

      The general rule is that omega-3 EFAs are of animal origin and omega-6 FAs are of plant origin. Your DHA comment shows you know the difference. A diet of fat from only plants would be so high in linoleic acid that it would be difficult to counter (balance) with omega-3 EFAs. The answer to your second question is that you would be one sick cookie.

      • Lowen Gartner

        I am not a vigilante. I’m not even a vegetarian let alone a vegan. However, I live among a bunch of Seventh-day Adventists who are strict vegetarians and quote studies from Loma Linda School of Health showing that the live much longer than the average person. I am curious how that computes with “you would be one sick cookie”. Just trying to learn. Thanks for your previous reply. I really appreciate it.

        • RachelH in Seattle area

          They may live longer than people on SAD, but not longer than a healthy LCHF person. Of course, there are no studies . . .

          • LeahS in Seattle area

            I would like to meet with like minded ketogenic lifestylers in Seattle area. Is there anyway to send my email address to RachelH in Seattle area so she could respond if interested? Thanks.

          • charles grashow

            “Ancient humans lived primarily on eggs, fish, animals, and other living creatures.”

            And the link to the study that proves this is where?

          • Alice and Fred Ottoboni

            It is challenging to receive a question from an inquiring mind. However, we are surprised that there is a mind in this day and age of nutrition blogs that thinks there is only one link that would explain the whole Paleo philosophy. The anthropology-paleobiology literature abounds with good information. Do some Google-ing and you will find all you need to know.

          • charles grashow

            If there are no studies to prove this then your statement is nonsense.

        • Alice and Fred Ottoboni

          Hi Lowen,

          Many thanks for responding; we admire your perseverance. We hope we can provide some information about EFAs that will be of value to you.

          About Seventh-Day Adventists, we have been very interested in their nutrition and lifestyle. They are a good people and are content with vegetarianism. So be it. However, about their morbidity and mortality, a search of the web shows that the statistics are all over the place, which just shows that statistics can be used to say whatever one wants them to say.

          About our answer to your second question, it is not as facetious as it appears. The thought of a diet containing only plant fat (basically vegetable seed oils) boggles the mind. For example, vegetable oils contain from about 25 to 80 percent omega-6 linoleic acid (LA) with essentially little or NO omega-3 alpha-linoleic acid (ALA). Thus, a mixture of commercially available vegetable oil has about 34,000 milligrams of LA in 100 milliliters of edible portion.

          Omega-6 FAs generally are highly inflammatory and pro-cancer, whereas omega-3 FAs are anti-inflammatory and protective. Omega-6s are harmful to the extent that their quantity exceeds the quantity of omega-3s. In other words, it is their ratio that determines their effect, not their individual totals. It has been estimated that the requirement for omega-3 in the current American diet is about 3,000 mg. Therefore, an amount of omega-6 in excess of 3,000 mg could be harmful. Much larger amounts certainly are. 34,000 mg (probably more) a day would be unthinkable.

          An added tidbit to encourage you to learn more about the importance of EFAs for your health is that linoleic has been shown to cause (or at least favor) breast, prostate, and colorectal cancers. The biochemical mechanism by which linoleic acid causes cancer and how omega-3 EPA (eicosapentaenoic acid) counters linoleic acid and prevents cancer is shown in pages 185ff in reference 2.

          Lowen, we encourage you to learn more about the subjects that Michael posts on Ketopia (not just about dietary fat) for the sake of your health and well being. We would be happy to answer any questions you may have.

          Keep learning!

          • Lowen Gartner

            Thanks for the reply. Much appreciated. I read this blog regularly and just finished The Modern Nutritional Diseases.

            I started this comment because I have been arguing this point (the need for animal fat) with an SDA friend and was looking for information. He claims he does not need fat from animal or dairy/egg sources because 1) he does not use seed oils, 2) he gets his fat from olive, coconut, red palm, flax, hemp, chia and pure MCT, and 3) he supplements with Algae-derived DHA to keep his Omega 6:3 less than 2:1.

            I haven’t been able to find anything that counters his argument.

            He also says that if he get’s his protein from pea, hemp, flax, chia sources, that it covers all necessary amino acids as hemp protein contains all 21 known amino acids.

            He does eat a ketogenic diet which is primarily raw.

  3. I couldnt say it better myself! Omega 6 fatty acids found in vegetable products are promoters of inflammation, while Omega 3 fatty acids (found in fish) reduce or counteract the effects of inflammation.

    So, one should supplement with Omega 3 and reduce the intake of Omega 6. The ratio of Omega 3 to Omega 6 that a human consumes should be 16:1, as I can recall.


  4. Lowen, I was a vegan for over a decade and it pretty much destroyed my body. Of course, I did not have all of the knowledge that your SDA friend has, and maybe I would not be in such bad shape if I had. One thing I can tell you for sure about plant foods that may be problematic for people on entered plant-based diets for a long time is that they contain toxins that a person may or may not be able to properly breakdown and eliminate from their body. For example, virtually all plant foods (vegetables, fruits, nuts, seeds, and spices, as well as coconut oil, olive oil, and avocados) contain a chemical toxin called salicylates. These salicylates are present in plant foods to help protect thelant from over-predation by herbivores. The concentration of salicylates increases inside the plant’s tissues when the plant feels threatened, thus deterring herbivore from consuming anymore of it for the time being. On a vegan diet, I consumed enormous amounts of plant food, thus exposing myself to a larger than average intake of salicylates. The result is that I have become entire unable to tolerate even the smallest amount of salicylate contain foods without experiencing a negative reaction. Coconut oil, for example, causes inflammation even with external application, to say nothing of me ingesting it. For the longest time, I could not figure why all plant foods basically made me sick, but once I learned that salicylates were the common denominator, it all made sense. So, even if I wanted to continue being a vegan for ethical reasons, it would actually be impossible for me to do so if I wished to continue walking upright on this planet.

    I can also say categorically that too much Omega 6 in my diet when I was a vegan cause extreme dysmenorrhea (painful periods), so it was clearly wreaking havoc with my hormones. Once I eliminated all plant foods and their oils from my diet, the dysmenorrhea was “cured.” 20 years of suffering for nothing!

  5. I truly appreciate this article. I actually am an former Seventh-Day-Adventist and I can tell you first hand they are not the healthiest people as their supposed statistics claim. Many are over weight with many different health issues and most of the ones I’ve known thought the years also take medications. That’s right. Pharmaceutical drugs for different ailments. I became very ill after becoming a member and going vegetarian and than vegan. Also, there are three different groups in this denomination. Most I’ve known are not strict vegetarians at all who eat meats as well as the eggs and cheese. . Then there are the ones who only eat eggs and cheese. Then that group I got involve with who are the strict vegans. They no better health, physically or emotionally. Many have depression, as I had and hormone issues. Many I’ve known have used anti-depressants, others still do. I am still trying to recover my health from this eating life style which stems form the premise of the writings of their “so-called” prophet, Ellen G. White, who was no prophet at all, which after much struggle, guilt, and ill health led me to do extensive research in this which I had not done when entering into the church, I just believed and followed all I was taught and read. So, as this article plainly tells, and it is by no means a sin to eat animal fat or products and will not cause ill health if only organic free range an grass fed animal products are used. I am so thankful for this article because I had been searching for the answers to the fat question and kept getting side tracked by fruitarians, the fear of fat groups, uninformed and ignorant health practitioners who still advise a low fat diet. I’ve done all the diets and the thing most lack is healthy fat! That is why I’ve never gotten well and have had enormous hormone issues and other problems. We need fat for our bodies to absorb and utilize the other nutrients from the foods we eat, for body heat and thyroid health, production of hormones that help run our endocrine and all other systems. Lack of fat even causes hair loss, as I have experienced. Instead of just trying to treat my thyroid by ill-informed health practitioners, the under lying problem is not always iodine, which many want to give, and in dangerous amounts, but in many cases it is lack of sufficient healthy fats. That’s what I have personally found having been around the block to many time to count on the roller coaster of ignorance in trying to recover my health with the lack of knowledge from the “fat phobic” groups. Lastly, I am not trying to say
    Seventh-Day-Adventists are bad people, as I was one for years. They are just deceived and ill-informed due to certain teachings promoted by the leaders who follow the writings of Ellen White. There are no biblical truths in not consuming animal products, other than the propaganda about veganism and its benefits put out by them and others not affiliated with them who have health reform programs speaking the ills of animal fats and animal flesh. I’m sorry this is so long, but I just had to comment on this. Again, I thank you for this article. I will endeavor to add more healthy fats back into my diet and stop jumping over multiple diet fences which have already proven to be unbeneficial and harmful for my recovery.


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