Can you handle fat?

No question: Low-carbohydrate diets generate improved postprandial lipoprotein responses.

Here's a graph from one of Jeff Volek's great studies:

Participants followed a low-carb diet of less than 50 g per day carbohydrate ("ketogenic") with 61% fat.   The curves were generated by administering a 123 g fat challenge with triglyceride levels assessed postprandially. The solid line represents the postprandial response at the start; dotted line after the 6-week low-carb effort.

Note that:

1) The postprandial triglyceride (area-under-the-curve) response was reduced by 29% in the low-carb diet.  That's a good thing.

2) The large fat challenge generated high triglycerides of greater than 160 mg/dl even in the low-carb group. That's a bad thing. 

In other words, low-carb improves postprandial responses substantially--but postprandial phenomena still occur. Postprandial triglycerides of 88 mg/dl or greater are associated with greater heart attack risk because they signify the presence of greater quantities of atherogenic (plaque-causing) postprandial lipoproteins.

A full discussion of these phenomena can be found in the Track Your Plaque Special Report, Postprandial Responses: The Storm After the Quiet!, part of a 3-part series on postprandial phenomena.

Comments (19) -

  • Gretchen

    3/21/2010 1:42:32 PM |

    My problem with Volek's study is that it's analogous to putting someone on a LC diet and then doing a GTT.

    They kept people on a low-fat high-carb diet and put others on a high-fat, low-carb diet and then did a lipid tolerance test.

    In both cases, your response to the nutrient (carbs in GTT and fat in lipid test) will be impaired because you stop producing enzymes you don't need.

    The people on the low-fat diet didn't tolerate fat as well as people who had been on a high-fat diet when suddenly challenged with a tremendous amount of fat.

    What I'd want to know would be the lipid responses *during* the 6 weeks on the two diets.

    What his results show me is that eating a high-fat diet makes your body adapt to burning fats. This is what I would expect.

  • David

    3/22/2010 1:13:51 AM |

    While these results are interesting, I wonder how relevant they are in a real life setting. The fat load that generated these results was 123 grams, which would be like eating 1.3 sticks of butter in a single meal, or like sitting down and drinking nearly 3 cups of heavy whipping cream all at once. Who does that?

    Dr. Davis, I know you are encouraging 3 hour postprandial TG checks in the TYP program via CardioChek. Are you seeing these types of postprandial results (viz. results similar to Volek's) following meals with less exaggerated (i.e. normal) fat intake?

  • Miki

    3/22/2010 9:40:34 AM |

    Here is prospective study done in Sweden with a follow up period of 12 years that shows a higher consumption of dairy fat like butter and cream is associated with a 45% reduction in risk for heart disease. "Nothing in biology must make sense except in the light of evolution"

  • ET

    3/22/2010 5:14:12 PM |

    After eating low-carb for over a year, my post-prandial triglycerides never go above 100.

    I do agree with Gretchen on the adaptation process.  I shudder to think what an OGTT test would show.  Maybe some day, I'll drop $70 to find out if I can get someone to take me.  I'll be in no shape to drive after consuming that much sugar.

  • zach

    3/22/2010 7:39:03 PM |

    I agree Gretchen. There can be a long adaptation period. Dr. Davis's patients are blessed to have him as their doctor, but I suspect he can't quite kick the lipid hypothesis!

  • Anonymous

    3/22/2010 7:45:57 PM |

    At least for me, I think Dr Ron Rosedale's diet is best.  Low carb, protein at 50 to 70 gms. No grain, mostly no dairy.  He says if you want to lose weight you need to avoid saturated fat because saturated fat keeps you insulin and leptin resistant.   Unless you drink olive oil, the diet winds up being low calorie.
    Hmmmm.  Maybe that is the answer.

  • donny

    3/22/2010 8:35:33 PM |

    I have to wonder what the mechanism is for high triglycerides causing heart disease? High triglycerides in a high carb diet usually means high insulin, high glucose vs fat metabolism,and low hdl. Aren't high triglycerides in a low carb diet a slightly different picture?

    Right or wrong, I admire your willingness to go against the tide (any tide) for what you see as right.

  • Stan (Heretic)

    3/22/2010 8:52:55 PM |

    Absolutely!  What amazes me is, in spite of their adaptation to a high fat low carb metabolism, the patients still saw their OGTT triglyceride results improve over time!  This is my experience too.

    There is no doubts, on a high animal fat diet or on a high fat diet of any kind, our tolerance to glucose is indeed reduced.  50g in one does is OK for me (I weigh ~65kg) but 100g in one go as sugar would still be too much and would make me feel sick (but the same amount of carbs in vegetables spread over a day would be ok).

    It took a good few years to improve my tolerance.  Right after (2 weeks after) I went on a high animal fat LC nutrition (in 1999) I could not tolerate even a 50g of sugar in one shot! Even one bottle of beer (~20g of carbs) would make me feel stomach sick + give me a headache.   It took me more than 2 years to reach this tolerance to carbs, and I even noticed some steady improvement from year 2 to year 7 into this.

    It is indeed totally illogical, although unsurprising given the present standards of medical science, to use big glucose shots to assert patients response under  predominantly ketogenic metabolism.

    It is a curious lack of curiosity on behalf of the mainstream medicine that no nutrition research group seem interested in studying the exact effects (all beneficial for me), vitamin and nutrient requirements (very different!) and adaptation issues on the high fat low carb diets.


  • Anonymous

    3/22/2010 10:37:06 PM |

    The last few posts have generated quite a few comments!!!

    Anonymous said...
    "The last sentence made me cry."

    Alfred E. said...
    "This is becoming more confusing by the minute. First, no carbs, only fats and protein. Now, no butter, no dairy, no, carbs, just a few drops of fat and protein. I am going to cry, like the previous poster."

    Dana Law said...
    "I've learned a lot but need some direct guidance. I find that making daily decisions on what to eat difficult. I want to eat healthy and have some variety. Here's the question. What do you eat? What did you have for breakfast this morning? What did you eat last night? What do you keep in the fridge and on the counter to make following your dictates easier. I don't want to over-think it but all this information is overwhelming."

    Helen said...
    "Again, with so many cautions of what not to eat, I'd love to see a Dr. Davis-approved diet plan. If I were just following all the Don'ts, I'd go crazy (and hungry)."

    The bottom line is that Jimmy Moore, William Davis, Matt Stone, Kurt Harris, Stephan Guyenet, Don Matesz, Art Ayers, Billy E., B.G., T., Mark Sisson, Richard Nikoley, Michael Eades, Matt Metzger, Peter, Arthur De Vany, Chris, Ryan Koch, Chris Masterjohn, Jenny Ruhl, Richard Bernstein, Fred Hahn, Jonny Bowden, Larry McCleary, Mary Vernon, Dave Dixon, Mike O'Donnell, Scott Kustes, Gary Taubes, Rob Wolf, Seth Roberts, Loren Cordain, Sally Fallon, Mary Egin, Keith Thomas, Tom Naughton, PaleoDoc, Nora Gedgaudes, Barry Groves, John Briffa, Laura Dobson, Dana Carpender, Keith Norris, Rusty Moore, Doug McGuff, Martin Berkhan, Bryce Lane, Erwen Le Corre, Dan, Drew Baye, Uffe Ravnskov, Eric Westman, Lierre Keith, Brian Peskin, Steve Parker, Jeff Volek, Stephen Phinney, Diana Schwarzbien, Barry Sears, Nina Planck, Lyle McDonald, T.S. Wiley, James Carlson, Steven Gundry, Keith Berkowitz, Richard Feinmann, Jan Kwasniewski, Konstantin Monastyrsky, etc., etc., etc. cannot come to a cohesive way of eating that is workable for everyone. My guess is there are not two of these people whose diet is identical!!

    Is it any wonder we are confused? Many folks are looking to emulate the diets of others - a method that will never provide personal optimal health.

    Take the time to watch/listen to the following lecture by Dr. Bruce German from UC Davis. It will help to explain why we have this conundrum.

    Then read the writings of a Venetian gentleman who lived to be almost 100 yars of age (Born 1467 - Died 1566).

    Both of these together put nutrition and health in perspective for me.


  • DaisyPatch

    3/23/2010 6:32:40 AM |

    Dr. Davis, please comment on the study released today by the Harvard medical School.  How does one avoid saturated fats and still get proteins if he is a low carber??  Thanks!

  • Dr. William Davis

    3/23/2010 1:57:39 PM |

    Hi, David--

    Studies are meant to make observations. That is the reason for the unnatural intake of fats.

    People on the Track Your Plaque Diet approach rarely show such high levels because they've reduced or eliminated the foods that form the basis for high postprandial responses (wheat, cornstarch, and sugars) and do not indulge in high fat intakes that cause near-term surges of postprandial particles.

  • Dr. William Davis

    3/23/2010 2:01:00 PM |

    Hi, Gretchen--

    I agree, but I believe that the observations are still relevant. It shows us that postprandial responses are sensitive to carbohydrate intake over time. It also shows us that average people have substantial surges postprandially with fat challenges on an average American diet.

    While I advocate carbodrate restriction and weighing diet more heavily in fats and oils, you can see that the emerging conversation is that unlimited quantities of oils, low-carb or no, have the potential to generate extravagant postprandial responses.

  • Gretchen

    3/23/2010 2:53:11 PM |

    I tested my postprandial triglycerides after having been on a LC diet for about 11 years and wheat-free even longer (because I discovered that it was wheat that was giving me acid reflux). With about 50 g of fat, the TGs went very high, over 400.

    Someone else said his rarely went over 100 after only a year on a LC diet.

    The author of "Life Without Bread" presented a graph showing that younger people reduced cholesterol on a LC diet but older people didn't.

    We may all react slightly differently to different diets (as well as interpreting them differently, as someone else has pointed out; you can be on a LC diet that includes mostly LC junk food or a LC diet that includes a lot of greens and lean meat).

    I have type 2 diabetes, and some people think that metabolic syndrome/type 2 diabetes is basically a disease of disturbed lipid metabolism.

    So what worries me is that people with insulin resistance, who may not respond the same way as people without IR, are taking LC advice to eat a lot of fat that is based on the experiences of people without IR.

    Here's an article that addresses this issue:

    This is why some time ago I felt the "GO Diet" by Jack Goldberg and Karen O'Mara, which is LC but emphasizes monounsaturated fat, yogurt, and fiber, was the best solution and helped them rewrite it as "The Four Corners Diet."

    Apparently very few people agreed with me, and the book bombed.

    I still think LC with restrained fat intake, meaning restrained calorie intake, and real foods along with reasonable exercise is the best solution on the basis of today's evidence.

  • Kurt G. Harris MD

    3/23/2010 4:05:03 PM |

    @Tom (anonymous)

    Although there are many voices and styles of presentation, I can state, through frequent communication with them, that my approach at PaNu is a tent that fully covers the diets of Eades, Dr. Stephan, Peter at Hyperlipid, Sisson, Nikoley, and although I do not correspond with them, Bernstein and Groves. There is also significant overlap with the Weston A Price Foundation and even Matt Stone.

    If you look for a common element in all of our approaches, and indeed the crux move in choosing a healthy alternative to the SAD, it is actually nothing to do with paleo so much as the simple and total rejection of Ancel Keys and the multiple versions of the lipid hypothesis he spawned 50 years ago.

    This then allows the realization that humans are evolved to eat substantial calories from animal products, including animal fats, and further including (on purpose, and without limitation or fear) SATURATED FAT.

    All versions of the lpid hypothesis have in common the belief that somehow, somewhere, there is a molecule that is fat, tastes like fat, is  kind of like fat, is associated with fat, or reminds us of fat, and that molecule is perversely designed to give us atherosclerosis and coronary heart disease.

    Start to view all these dietary approaches through the filter of whether they reject the lipid hypothesis instead of "low carb" or "paleo" and the dividing line will start to look much much brighter.

  • Anonymous

    3/23/2010 11:47:32 PM |

    So for someone that works out a lot and is suppost to gte something in the 3000-4000 calories per day... what would be the addecuate kind of food to use as high calories source?
    I was taking unlimited almonds, but this post makes that look like way too much fats.

  • Anonymous

    3/24/2010 4:37:31 AM |

    @ Dr. Harris,

    You obviously did not read/listen to the two links that I provided in my comment.  I happen to believe every word you wrote in your response.   My contention is that personal optimal health and longevity is beyond the simplicity of following 12 simple steps (though I do think they are a huge step in the right direction).  Health is determined at the molecular level based upon an individuals genetics as affected by many factors, particularly, stress. Please Google nutrigenomics, epigenetics and metabolomics.

    My apologies to Dr. Davis.

    (I may have inadvertantly sent a another version of this comment previously.)


  • Pythonic Avocado

    3/25/2010 3:21:41 PM |

    Isn't this just normal for a well adjusted human? I mean TGs are how fuel (free fatty acids) is transported through the blood from its sources (liver and fat cells) to the places where it is needed i.e. everywhere else.

  • Anonymous

    3/28/2010 2:00:14 PM |

    @ Pythonic Avocado

    Yup, eating fat raises TG levels temporarily.  I consume a high-fat diet with lots of nuts, and, based on results from a TG meter, do not see extraordinarily high TG levels (starting from a fasting level near 70).  I also spread meals out during the day, thereby reducing both BG and TG spikes.

    The only time I saw a high TG spike was after consuming 2 raw egg yolks!  This influenced how I approach eggs (always cooked, one at a time, mixed with other foods).

    btw, if you consume too much fat in one meal, a lot of the fat will end up in your stools, since there is a limit to the lipase that your pancreas can generate on short notice.  Another complication when trying to compare diets.

  • buy jeans

    11/3/2010 3:44:13 PM |

    In other words, low-carb improves postprandial responses substantially--but postprandial phenomena still occur. Postprandial triglycerides of 88 mg/dl or greater are associated with greater heart attack risk because they signify the presence of greater quantities of atherogenic (plaque-causing) postprandial lipoproteins.