One man’s journey on LCHF: Making sense of science, dogma, and reality
An excellent (longish, but good read) piece by lay LCHFer and curious lay scientist Malcolm McKinlay.
We all know that if you eat a lot of fat, you will get fat and put yourself at risk of cardiovascular disease. We all know that if you eat too much and don’t exercise enough, you will become fat.
I’ve been carrying out an experiment on my own body for the last three months. During that time, I’ve drastically changed my eating habits and I’ve done a lot of reading and research.
However, I’m not a nutritionist. I’m not a doctor. I’m not an epidemiologist. You really have no reason to take anything I say seriously.
Nevertheless, I am a bit of a geek. And this is what I’ve learned so far.
- Eating a lot of fat doesn’t make you fat
Okay let’s take a deep breath at this point. The supermarket is heaving with low fat products that come with heart foundation ticks. That is what makes them healthy, right? High fat versions are not healthy. Right? Wrong!
I know. This is hard to accept. But hang with me.
If you have a high fat AND a high carbohydrate diet (sometimes called the ‘standard American diet’) you will get fat- but it is not because of the fat. It is because of the carbohydrates.
The physiology of this, as much as I understand it, seems to work like this. When you eat carbohydrates, the pancreas releases a spike of insulin that enables the body to process the carbohydrates so that energy can pass into the cells.
This same process instructs the body to store the fat. Hence, you get fat.
However, if you eat a high fat diet without a high level of carbohydrates, the body will quickly learn to use the fat as fuel, which doesn’t require any special physiological process. No insulin is necessary.
There are plenty of things I find confusing in the world of nutrition. But here is one thing that seems to be beyond dispute. If you adopt of low carb/high fat diet (LCHF), you will lose weight. You don’t have to count calories. You don’t have to worry about overeating fat. Unlike carbohydrates, fat is very filling (satiating). You will feel full quicker and eat less.
I don’t expect anyone to accept what I’ve said so far very easily. It’s taken me a while to accept it. But after three months, it is no longer controversial for me.
Grant comment: right on – insulin controls the whole process and high insulin is a problem for many people and it is the start of the disease process. Insulin turns off fat burning and promotes storage. It’s anabolic, which is good, but not what you want ALL the time.
- Eating a lot of fat will not give you heart disease (as long as you have low carbs)
But what about your cholesterol, right? Aren’t you clogging your arteries and putting yourself at risk of a heart attack?
The fact is that cholesterol is far more complicated that we’ve been lead to believe. A high cholesterol reading is meaningless.
You’ve probably heard of good cholesterol and bad cholesterol. This is how it breaks down.
HDL is the good cholesterol. And high fat diets (with low carbs) raise HDL levels. In fact, saturated fat (like that found in fatty meat) is good for this. I can see you wincing. But hang with me. (And I believe that some people within nutritional orthodoxy now agree that saturated fat is ‘neutral’ in its impact on cardiovascular disease).
LDL is generally considered the bad cholesterol. But that isn’t the whole truth. LDL can consist of large fluffy particles or small dense particles. Large particles of LDL are harmless. Small particles are dangerous and are a risk factor for cardiovascular disease.
And the evidence seems to be that diets high in fat and low in carbs raise the level of large particle LDL- not small particle LDL.
When testing your cholesterol, the key thing to look for is your level of triglycerides. If these are high, that is bad news. High HDL is a good thing. High LDL may be fine if triglycerides are in a normal range.
I’ve met two nutrition academics from my local university to see what they think. One of them agrees with what I’ve said 100%. The other is still nervous about saturated fat.
Grant comment: Pretty much right on. I’d add that triglycerides can be used to proxy the presence of the small dense LDL (ApoB phenotype). TG’s less than 1.5 are good, but closer to 0.8-0.9 means almost all of your LDL particles are large, probably benign large buoyant particles (ApoA Phenotype).
So you want a high HDL, Low TG. The total cholesterol and LDL numbers on their own are old science and practice. Let’s move on. One exception to this might be familial hypercholesterolemia. Some small percentage of the population don’t react in a way that’s usual to LCHF type diets and end up with very high total cholesterol numbers (11-12 mmol or in that range). We don’t know about the dangers of this in the context of a LCHF diet. I would probably err on the side of caution here and eat less fat.
Eating fat in the context of highly processed or high carb diets might be an issue for some people – especially the insulin resistant. There are studies showing carbs plus fat spike insulin above the carb alone level but only for people who are insulin resistant.
- If you are fat, it is probably not driven by the fact you eat too much and don’t exercise enough
Nutritionists love to talk about ‘energy balance’. If you eat too much, and don’t burn enough calories in exercise, you will store fat on your body. That energy has to go somewhere right?
However, there is another way of looking at this that has taken me a while to get my head around.
The ‘energy balance’ idea is pretty persuasive logically. But it assumes that the human body is like a black box that will process all food (in the form of calories) the same way.
Our bodies seem to be more amazing than that. A healthy body has a way of regulating its fat tissue and hence its weight across a very narrow range at a healthy level. You could call these people metabolically well regulated.
We all know people who can eat and eat and eat, and they never put on weight or lose weight. (I’m not one of those people).
What if eating certain types of food upsets this regulation process in some people? The argument seems to be that some people have a hormonal or metabolic reaction to large amounts of carbohydrates.
I don’t pretend to understand this comprehensively, but this disorder of excess fat accumulation has nothing to do with ‘will power’. Sugar and carbohydrate consumption generate insulin spikes. Insulin promotes the storage of fat cells. It seems years of insulin spikes can lead to the body becoming insulin resistant. And that, dear readers, is a recipe for obesity and diabetes.
The body will still regulate its weight but this won’t be at a healthy level; for some people, this will be at a level of obesity.
The ‘energy balance’ argument is that these people are simply eating too much and not exercising enough. They are greedy and ill-disciplined.
The ‘metabolic syndrome’ argument is that these people have become metabolically disregulated through consumption of high levels of sugar carbohydrates. This drives their appetite crazy. They have to eat more (and often they have to become less active), and they especially have to eat more sugar and carbohydrates which feeds further hunger. They have become physiologically addicted to sugar and carbohydrates.
The body is no longer able to hormonally regulate its fat tissue across a healthy range. Without that hormonal regulation, people become overweight.
Wading through all the reading on the topic is tough work. But I found the research on overfeeding particularly interesting.
Subjects who were fed primarily fat in the overfeeding process were simply unable to get close to the calorie consumption targeted in the studies because they felt so full.
Those who were fed high carbohydrates and high fat, however, could easily take in thousands of additional calories and still feel hungry two hours later.
The argument here is that all calories are not equal. Calories from fat are ‘good’. Calories from sugar and carbohydrates can be dangerous for some people.
Quality of calories is more important than quantity.
And what about balance? Moderation in everything right? You don’t want to get too extreme right?
A prescription of LCHF is inherently not ‘balanced’. But some people who eat moderate carbohydrates and moderate fat seem to develop these negative hormonal and metabolic reactions, and in some cases develop addictions to sugars and carbohydrates.
This prescription therefore, is not about balance. It is about avoiding ‘bad calories’ and choosing to eat ‘good calories’.
Grant comment: Pretty much spot on. The energy balance argument is of course by definition true. But truisms give us no clue to the mechanism – the energy balance tends to ether argue for a lack of self-control or a pathological food environment, or both. Again, truisms. But we do know the hormonal environment that is a result of insulin resistance and dietary composition affects the energy in/out homeostasis.
- If this is all true, how is it possible that the nutritional authorities have got it so wrong and continue to get it so wrong?
It is fascinating to look at the history of thinking around diet, obesity and weight loss in the last 150 years. And I have to add that this is something that the LCHF advocates discuss at length.
For 100 years up until the 1950s, research on weight loss commonly prescribed avoiding carbohydrates- bread, potatoes, pasta, rice, oats etc. The first famous example is the ‘Banting diet’ from the 1860s.
In the 1950s, America became terrified of coronary heart disease. There was a sharp increase in deaths from heart attacks. And this is where Ancel Keys hits the scene. (LCHF people often start playing Darth Vader’s theme at this point).
He published the ‘seven country’ study that shows a relationship between the consumption of saturated fat and coronary disease. He featured on the front page of time magazine in 1961; and his charisma and leadership had a big impact on the modern field of human nutrition. And he believed passionately that the way to a health heart is through low fat, low cholesterol diets.
His thinking gained traction at a political level and his influence over nutritionists around the world was powerful.
For a while, his critics argued against his thesis, pointing out that it is sugar, not fat, that is the culprit for many health issues. Others pointed out a number of problems with Ancel Keys’ famous study- like the fact that there were actually over 20 countries in the study; but he ignored any evidence that would refute his thesis- including just the seven that fitted his hypothesis.
But he succeeded in writing off his opponents as quacks, and his views came to dominate the field. And in NZ today, it is still hard to find any nutritionist who doesn’t share the party line on low fat diets (although I have found one who is happy to criticise Ancel Keys’ work as fraudulent).
I’m not suggesting there was any great conspiracy at play here. But it does interest me that most nutritionists seem to lack any curiosity when it comes to LCHF ideas, and instead adopt a uniformly hostile posture.
The international advocates for LCHF diets nowadays are rarely nutritionists or dieticians. Instead they are cardiologists, sports scientists and neurologists. They come from related fields but are not part of the dominant nutrition paradigm.
They tell a common story of initial scepticism of LCHF ideas, of personal experimentation, of taking a closer look at the nutrition literature, and then of becoming hugely critical and dismissive of the nutritional ‘low fat’ status quo position.
“Isn’t it interesting that after 40 years of dominance and research, there are no studies that can yet demonstrate that low fat diets prevent cardiovascular disease or promote weight loss? In fact, since its adoption, diabetes and obesity has gone through the roof,” they chorus.
Grant comment: Yes probably it might have happened like this. I’m not sure there is any great conspiracy theory that is true. That usually requires a level of organization, which is beyond most of us and almost all governments and institutions. We weren’t there and the winners usually record history. Who knows the whole story?
To be sure, science and medicine often starts with plausible hypotheses – like the lipid hypothesis, but they just don’t turn out to be true. The problem is that the process is very slow moving and people are so caught up in seeing the world their way, they can’t easily change. That is something I keep telling my staff and grad students. We all run the chance of only seeing the world one way.
Bottom line: We know better now, and thankfully the world has changed so that a few academics no longer hold the power of the “anointed” to tell us what to eat. The intelligent blogger and open access journals through the Internet have changed everything. This is hopefully true across the whole scientific process. Hopefully peer review is dead, and open review is the new way.
So that is how we got here.
- Processed food described as ‘low fat’ is probably bad for you. Avoid them and eat ‘real food’ instead.
There is much in the nutritional literature that is confusing for your average punter like myself. I can understand people having different perspectives. But there is one thing about which I am angry.
Low fat food in supermarkets is healthy right? Right? Wrong again!
When they began taking fat out of food because of the public’s fear that it contributes to cardiovascular disease, the food companies found that it became unpalatable. It tasted disgusting.
So what did they do? They replaced the fat with sugar- much of it high fructose corn syrup. The next time you are in the supermarket, have a look at how much sugar there is in the foods you buy, remembering that 4g represents one teaspoon of sugar.
And there is no nutritionist who will tell you that eating piles of sugar is good for you. And yet, there it is. Piles of sugar in almost all food that is advertised as ‘low fat’ and healthy.
That smells like a scandal to me. I find the hypothesis compelling that this is a key driver in the obesity and diabetes epidemic raging through the Western world.
Grant comment: The conflict of interest between some of the NGOs we trust like the Heart Foundation through the tick program, and various food industry PR techniques are a scandal and no longer publically acceptable. While we all agree that processed food is a problem and we need to concentrate on real food that is a ways away from the industrial food supply.
This change will be driven by you and your choices in the market. We can’t wait for the government or the Heart Foundation to lead us.
- My journey
“How strange do you want to be?” I friend enquired when I told him about my dietary experiment. It is the social (or should I say ‘anti-social’) dimension of this that has been the trickiest factor for me thus far. But on the plus side, I do far more cooking and I eat far more vegetables than I’ve ever done before.
I was first introduced to the idea of fostering a fat burning metabolism rather than a carb burning metabolism by an elite ultra-distance runner, Claire Akin-Smith, who was helping me with my running technique. I then read an article in the Listener which featured Prof Grant Schofield (Public Health and Sports Science, AUT- an advocate of LCHF diets) and Prof Jim Mann (Human Nutrition, Otago University- a sceptic). This lead me to a YouTube lecture Schofield gave. Then I heard Nina Teicholz on the radio (author of ‘The Big Fat Surprise’). A cursory look on the internet then lead me to Prof Tim Noakes (Famous Sport Scientist from South Africa- a huge advocate of LCHF diets), Dr Steve Brukner (a sports doctor, formerly with Liverpool FC, and now with the Australian test cricket team), and Dr David Diamond (Neurologist, University of South Florida). You can Google all of these people if you are interested.
And finally, I began reading award-winning science journalist, Gary Taube’s exhaustive book ‘Good Calories, Bad Calories’. It’s not an easy read.
But I felt compelled to give it a try. For the last three months, I’ve been experimenting with a LCHF diet. Bacon and eggs for breakfast. Salad with cheese and meat or fish for lunch. Vegetables and meat for dinner. And berries and cream if I need a dessert.
And the results have been the following:
- My digestive system has been working better than it has for almost two decades. This feels like a miracle. I’ve heard it said that eating a lot of meat can cause bowel cancer. But that is very hard for me to believe given how my bowels are so much healthier.
- I’ve been losing fat around my belly. Previously, no matter how fit I’ve been, I’ve always retained belly fat. I’ve never been a six pack kind of guy. But I’m down to the lowest notch in my belt and previously unseen ab definition is beginning to form.
- A wart on my face has dramatically reduced in size and almost disappeared.
- More than one person has described someone else as being ‘not in as good shape as you’. Unprecedented.
Now, it is possible to interpret these results in different ways. Perhaps the problem has not been ‘all carbs’ but only certain carbs- like bread and pasta and gluten. I’d be happy if that was the case. But as yet, I don’t know.
I’m eating more vegetables now than I’ve ever eaten before. Perhaps that would have some health benefit regardless of the carb/fat issue.
But it is also possible that my metabolism is sensitive to sugar and carbs. And by taking them out of the picture, my body is simply functioning in a far healthier way.
I’m sure my thinking on this will evolve. I repeat. I’m not an academic in this field. I don’t read the published research myself. So no one should be persuaded to change their diet solely by a blog post like this. But given everything I’ve read and heard, I decided to begin an experiment with my body. And for me, it actually began by wanted to improve as humble running efforts.
But I have a host of unresolved issues, including:
- I’ve heard that the nitrate in bacon can be bad for you- and I’ve been eating a lot of bacon. I don’t know what to do about that.
Grant- yes processed meat isn’t something we should go crazy on – at least get the least processed bacon fresh from your butcher
* And I don’t think the planet needs everyone to start eating more meat. I don’t know what to do about that either.
Grant: that’s an interesting argument – I don’t know the answer to. But a counter is threefold: First, if we are eating more whole animals, at least we aren’t going to waste everything except the lean muscle meat which we do now. Second, the overall amount of protein is moderate and shouldn’t change from what we eat now. So you can get that from all sorts of places including meat. Third, although vegetable farming is less intensive it also produces way less calories. So what we are we comparing here? Oh another point, part of the reason for the massive population gain is industrial farming. We have too many people to feed because of this. The grains caused the problem in the first place? Read “Against the Grain”. Good book.
But being a man of little brain, I can only cope with one question at a time. And so far that question has been- ‘What food is the best for my health’.
Grant: Unlikely your brain is limited or small. You sound just like a smart guy to me…..
I would be really interested to hear from anyone out there who has tried this kind of diet. And I’d also be interested to hear from any critics who can point out important weaknesses in my lines of thinking.
This is where I’ve got to so far. And my body feels like it is in the best shape it has been throughout my adult life.
Soon, I’ll get my bloods tested. If it turns out my triglycerides are up to dangerous levels that will be a real bummer, and will cause a rethink. I hope they are okay.