The death of the low-fat diet

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Healthy high-fat food

It’s February 25, 2013, and the low-fat diet is dead.

The low-fat diet has been on life support since 2006, when the failure of the WHI trial was published. A low-fat diet did not succeed in preventing heart disease. Instead people with pre-existing heart disease had a 30 percent increase in risk of heart disease!

Now it’s game over. Today the result of another large trial is published in the The New England Journal of Medicine, the most prestigeous scientific journal in the world for this type of research.

About 7,500 people were randomized to either get advice on a low-fat diet or a Mediterranean diet with more fat, specifically olive oil or nuts. After almost five years the trial was stopped in advance. The result was clear. The group getting the low-fat diet advice got significantly more heart disease, again.

NEJM: Primary Prevention of Cardiovascular Disease with a Mediterranean Diet

An earlier report from the same trial looked at the risk of diabetes. People exposed to low-fat diet advice had a much higher risk of getting diabetes. And study after study show that people have a harder time losing weight on a low-fat diet. So it’s more obesity, more diabetes and more heart disease on low fat.

R.I.P. low-fat diet. Welcome back, fat.

Continued: What the Dangerous Low-Fat Diet Looked Like


  1. If the "Low Fat" group were eating more carb's than the other group then how can we tell if it is the extra carbs or the low fat that's causing the difference?
  2. That's a pretty odd study. I've been looking at the data in the appendix to that study, and I found something peculiar: the three diets studied are almost identical in their macronutrient ratios:

    At the beginning of the study, the two Mediterranean diets had a total fat content of 39.2% (SD ± 6.9) and 39.4% (SD ± 6.5). Almost identical, in other words.

    But the low-fat diet was 39% (SD ± 7.0)!

    Something must have changed over the course of the diet, right? Not really. The Med diet fat composition went up by ~2%, and the low-fat diet fat composition went down by ~2%.

    All the ratios and micronutrient percentages are like this: almost identical across the three studies.

    It's almost as if they were trying to keep the macronutrient rations identical, so they could claim that the benefits were the result of the olive oil and the nuts, who coincidentally sponsored the study. Although even the olive oil intake was nearly identical.

    Really odd...

  3. Wade Henderson
    "low-fat" is dead. Talk about jumping the shark in pronouncements.

    What exactly was declared to be "low-fat" in this study.
    Well all groups began at about 39% of calories as fat.

    After almost 5 years the "low-fat" control group was ....drum roll.... down to 37% of calories as fat.

    The higher fat, olive and nut groups increase their total fat to 41.2% and 41.5%, hardly "high-fat".

    A little scientific honesty in reporting please.

    What this study does do, is compare a standard diet to a diet that raises either nuts or olive oil.
    The study participants were given the nuts and olive oil and did increase consumption.

    Of course they also ate more veggies and more fruits.

    Results -- There was no significant reduction in heart attacks, death from cardiovascular causes, or death from any cause. They only found a significant reduction in death from stroke . There was a reduction in cardiovascular causes only when these were pooled with deaths from stroke .

    One wonders if it is even possible for people with a specific point of view to read such reports without self administered distortion.

    Reply: #5
  4. Mike H
    It is funny to me that the "Mediterrannan Diet" seems to be the politically correct term for low carb.
  5. Dr. Andreas Eenfeldt, MD Team Diet Doctor
    So the long-term diet compliance wasn't great. It never is in a RCT. Wait for that and you'll wait forever.

    The statistically significant difference was in the primary endpoint: major cardiovascular events. It's what the study was designed to look for.

    Reply: #6
  6. "So the long-term diet compliance wasn't great."

    Did you read the study?

    "Changes in objective biomarkers also indicated good compliance with the dietary assignments (Figure S4 and S5 in the Supplementary Appendix)."

  7. Christa
    Even though the control group received low-fat dietary advice their fat intake was 37(± 7.0)% of total energy intake... you can hardly consider that a low fat diet!

    Especially versus 41.2 ±5.4 and 41.5 ±6.1% fat intake in the intervention groups.

    [Low fat diets usually <30% total fat]

  8. Wade Henderson
    Christa, and for purposes of comparsion when batting theories back and forth, usually the "other side of the coin" is the likes of Ornish, McDougall, and the China Study crowd.

    If they are uses as the typical "low fat" model, then you need to look at 10% of calories as fat.
    Certainly nothing above 15 to 20 percent. So to compare this study using 37% as a example of "low fat" is simply absurd and intellectualy inappropriate..

    This study is good and useful, but only when looking closely at the actual facts, groups, and diets involved. Simply labeling something to fit a needed foil is wrong.

    I could easily tell a person on a standard diet to follow this version of the Mediterranean diet assuming they were unlikely to do anything more intensive.

    Reply: #12
  9. .
    Although I agree with nuts as a healthy addition, this study looks slightly fudged, given the difference in results aren't that amazing for the fudging that has taken place, namely:

    1) Very cheekily, Med Groups to eat 2 servings of vegetables per DAY, control group 2 per WEEK
    2) Control Group forced to continue/start consuming refined carbohydrates, like bread, pasta, white rice, at their unfortunate peril
    3) Legumes (highly beneficial) are added to the Med Group
    4) Med Groups are given high polyphenol olive oil, unprocessed, unlike the oil the public buy in a store
    5) Med Groups are allowed to eat Sofrito, which contains herbs, garlic & yet more vegetables

    All groups should have eaten exactly the same food, with the Med groups having the addition of nuts/olive oil. Clearly too many variables have been used here.

  10. Theo L
    More than any great difference in the fat content of the two diets, what leaps out at me from the table of dietary advice given to the two groups is the following contrast

    Mediterranean: = 3 servings/**day** (!!) of bread, potatoes, pasta, rice

  11. Theo L
    Sorry. The greater than/less than signs got stripped out of that last post.

    More than any great difference in the fat content of the two diets, what leaps out at me from the table of dietary advice given to the two groups is the following contrast

    Mediterranean: <= 3 servings/week of bakery goods, sweets, pastry


    Control Group: >= 3 servings/**day** (!!) of bread, potatoes, pasta, rice

    Reply: #13
  12. Theo, that's what I mean't to say in my first post! This is also pointed out in Dr Ornishes huffington post article on this study.

    I am not in one camp or the other I am just interested in the facts. I have not read the study.
    Assuming this is true refined/processed("beige") food again not shown in a good light I'm afraid.

  13. HighlySkeptical
    Upshot: Olive oil is good for you. Eat lots. Is this news to anyone?
  14. Laura
    Your desire to prove the lowcarb diet unfortunately overwhelms your objectivity.

    The "lowfat" diet was far from low fat. AND, the lowfat dieters failed to comply with the diet set out.

    Wouldn't it be wonderful if we were all devoted to finding the healthiest diet, and not our preconceived notions.

    Reply: #16
  15. Ed Terry
    Dean Ornish was right in saying that the control diet was not low fat. His assertion that a 10% fat diet can lower mortality however, has never been proved. His studies included multiple variables and to state that the variable that mattered was fat is simply unproven. It would help Dean Ornish's argument if he actually performed a valid experiment instead of just speculating.

    What I find amusing is that the critics of this latest study argue that anybody who considers the study valid is filled with preconceived notions. That by definition is a preconceived notion.

  16. KetoDude
    According to this, the Low Carb Diet is also dead:

    It seems that eating "large amounts of fruits" and "moderate amounts of whole grains"
    is good for you.

    Which one to believe ?????

    Does one have to be wrong and the other right ?

    Replies: #21, #22
  17. Troy Wynn
    Do people just like to argue? How hard is it to connect the dots. Place your bets. Your health depends on it. I will follow human history, human biochemistry, clinical trials, and clinical practice results. It's pretty clear: eliminate flour, sugar, seed oils, HFCS from your nutrition. Eat real food. KEEP INSULIN FROM SPIKING... that means keep blood sugar down. Hello??? anybody get it yet???
    Reply: #20
  18. FrankG
    I can only assume that some do just like to argue :-( I see regular commentators who only have negative things to say about this blog... so WHY do they bother coming back and reading it?

    I've visited other blogs that caught my interest, only to discover that I do not agree with the points of view being expounded there. I've offered my opinion but after realising I am talking to a brick wall have moved on.. why waste my time?

  19. Clover
    I'm not sure if you linked what you intended to, the page I got to from your comment was just 'advice', it didn't have a single reference to back it up. Anybody can claim one diet is better than another, but it's not worth listening if they don't present sound evidence.

    According to this, the Low Carb Diet is also dead:
    It seems that eating "large amounts of fruits" and "moderate amounts of whole grains"
    is good for you.
    Which one to believe ?????
    Does one have to be wrong and the other right ?

  20. Jennapher
    Uhhh... Thanks for the Mediterranean guide? That's not even a study.. It doens't even say where this supposed research came from or what kind of study it is which is very important.. Either way I don't need any research to know that this is the best health choice. For years I have attempted to make the SAD work for me... I've tried weight watchers, jenny craig, doing it on my own, and other various "lifestyle changes" none of which lasted very long and most of which left me hungry most of the time.
    I'm a mother of 16 month old twins and ever since they were born my body has been deteriorating from lack of sleep and stress from working, going to school, chasing babies, and still having to get dinner on the table. Both of my shoulders were going out almost everyday for the past year and a half, my knees have been constantly hurting since February 2012, i'd gained 65 lbs since I had the twins and about 3 months ago I started to feel an arthritic-like pain in my hands. I'm not sedentary either... I'm a walker and i've probably taken a 30-35 minute walk almost everday since I was about 11. THEN I started this diet about 3 weeks ago.. after the first week my energy levels were through the ROOF... I was bouncing all over the place with all the energy I had.. I couldn't believe it I felt like supermom! As of today my knee pain and the pain in my hands have completely vanished.. My shoulder pain is still bothering me but only on my right side and it's not as intense.

    aaannd... I've gone down one whole size... My pants used to be so tight that I could almost not fit into them anymore which was one of the reasons I started this diet.. I said to myself.. JENN! You're either going on a diet or going to buy new pants and the thought of going one more size up made me SERIOUSLY SAD and now those pants are all loosey goosey on me! :D

    Oh and side note: Not even a slight increase in exercise and I still got all these amazing results!

  21. Nice article. This is a very nice topic for many of us. Have a healthy habit while making your body fit.
  22. They were talking about this study on CNN last week and they totally got it wrong (and I got kind of angry because of it).

    The news mentioned that a typical mediterranean diet contains "... whole grains ..." in it. NO, it doesn't.

    One thing the study didn't have in Table 1, however, was besides the recommendation to avoid baked goods it didn't mention anything about avoiding or recommending pasta in the mediterranean part.

  23. Kim
    I've read that low-carb diets contribute to arteriosclerosis. What are your thoughts on this?
    Please could someone answer this; I am so confused about which eating plan to follow. I've tried them all and the only thing that has worked is low-carb, but now I'm concerned about its risks.
  24. Zepp
    Noe.. rather high carb diets!

    Its a missconception.. high LDL levels can contribute to Aterosklerosis.. or it is rather a sign of higher risk!

    High fat diets almoste rise the HDL and making bigger LDL.. bigger is less prone to get stuck in the artery wall!

    High carb diets.. perticuly fast carbs.. provoke a higher insulin level.. and thats induce the liver to make more and smaler LDL!

    "Dr. Doucet understands the relationship between refined and processed foods, inflammation, oxidative stress, cholesterol and atherogenesis. He agrees that cholesterol is probably the innocent bystander."

  25. Myf

    I have looked at the table re dietary advice given in this study, and it does indeed look like standard low fat diet advice. I would question whether the advice given is the same as the diet followed, which appears to be the premise on which you are working... the fat contents of the diets were NOT very different, as the authors state:

    "We acknowledge that, even though participants in the control group received advice to reduce fat intake, changes in total fat were small and the largest differences at the end of the trial were in the distribution of fat subtypes."

    So it seems to me that claiming this as support for LCHF may be slightly misguided? And I say that as someone who is firmly convinced that the overall evidence is indeed in its favour. If you have time, I'd be interested to hear you thoughts on this specific point, rather than linking back to "what the diet looked like"?

    Thank you for a fantastic and thought provoking blog by the way!

  26. Zepp
    Yea.. I think that this study say that if one get free olive oil or nuts, one eat those and cut out other foods!

    Soo, its says that free olive oil and free nuts is good food!

  27. vkool
    Low-fat diet did not succeed in preventing heart disease but it is still a good diet to follow. Eating too much fat, people may suffer from disease relating to coronary. It is wise not to eat too much fat and I always prefer low-fat diet to others.
  28. Eric Anderson
    Look up the A to Z die study

    You tube presentation

    Take aways

    You ca tell people to eat 10 % or 30% protein. They may initially comply; but over time people drift back to the average 15 to 20 percent of calories from protein.

    Both sources and amounts of carbohydrates matter.
    Sugar and grain (Not so good)

    Even the type of fat can make a big delta and needs to be bette stuudied
    Synthetic oils of the last 200 years high in omega 6 and low or zero omega 3's like corn oil, soy oil, canola oil etcetera that are mnufactured at high temperatures are cheap and everywhere. What is the health effect? Don't look for the salad oil people to pay for the good studies or the USDA. ERic

  29. Paul
    Personally. I don't need these studies to prove anything. Was on low fat diet for diabetes ldl 325, weight 340, high blood pressure, high cholesterol, every health marker bad. Went on lchf weight 260 ldl 80, high blood pressure gone, cholesterol normal. Study enough for me.
  30. 1 comment removed
  31. Sandra Fuller
    Yes I recently upped my animal based fat and decreased my complex carb content when I kept experiencing exercise induced hypoglycemia during long hard intense workouts.Once I did this no more hypo incidents.Tried plant based fats but didn't work.I eat fish,eggs,chicken,red meats,pork,venison,rabbit.This is 60-70% of my diet and rest is complex carbs,animal and plant proteins,oils.Roughly 3500-4000 calories a day.

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