Diet wars: Can you really eat fat and get lean?

Grant Schofield doing the weekly LCHF shopping sans vegetables
Grant Schofield doing the weekly LCHF shopping sans vegetables, still to be purchased

There’s a food fight cooking…

In the red corner, we have the national nutrition guidelines, with its support crew of dietitians and most of the conservative medical and scientific community. They are the reigning public health champions. They are undefeated, but then they haven’t been seriously challenged. Until now.  In the blue corner, we have a new challenger. He’s been around a while but till now he’s just been shadow boxing. For some reason he strikes fear in those around him. I present to you…..Fat.

We’ve been told for decades now that saturated fat is the major enemy in the battle against obesity and chronic disease. Reduce your fat intake and eat more carbs instead we’re told.  Carbs are essential for human health we’re told.  Eat less, move more we’re told and you’ll stay in shape.  Here are the National Nutrition guideline for New Zealand.:

  1. Maintain a healthy body weight by eating well and by daily physical activity.*
  2. Eat well by including a variety of nutritious foods from each of the four major food groups each day:
  • Eat plenty of vegetables and fruits.
  • Eat plenty of breads and cereals, preferably wholegrain.
  • Have milk and milk products in your diet, preferably reduced or low-fat options.
  • Include lean meat, poultry, seafood, eggs or alternatives.
  1. Prepare foods or choose pre-prepared foods, drinks and snacks:
  • with minimal added fat, especially saturated fat
  • that are low in salt; if using salt, choose iodised salt
  • with little added sugar; limit your intake of high-sugar foods.

As well:

  1. Drink plenty of liquids each day, especially water.
  2. If choosing to drink alcohol, limit your intake.
  3. Purchase, prepare, cook and store food to ensure food safety.

* At least 30 minutes of moderate intensity physical activity on most if not all days of the week and if possible add some vigorous exercise for extra health and fitness.

Yep, that’s the advice and what I have been preaching publicly for the last 15 years, and practicing privately for my whole adult life.

So what’s the problem? The guidelines seem sensible right?  They’re evidence based, and the evidence is extensive right? Yes, sort of, and no.

Let’s deal with the Yes’s first:

Yes, there is extensive and compelling evidence that the type of diet described above is better for you than the Standard American Diet, henceforth known as the SAD :(.  This evidence is from randomized controlled trials, detailed longitudinal studies, and correlational studies.  There are plausible and known mechanisms for some of it, especially whole foods and meats. The important and convincing data around exercise and health is reflected in the guidelines too.

But that’s compared to the SAD.  It’s like saying that because studies show that smoking filtered, low tar cigarettes results in better health, less lung cancer, stroke, and heart disease than smoking roll your own cigarettes, that we should all smoke low-tar cigarettes. Bogus logic. 

The Sort Of’s

  • Sort Of: The part about maintaining a healthy body weight is true – that is good for you. And eating healthily certainly is the way to do this. A low fat diet could make this possible but in the 18 randomized controlled trials to date, where low fat diets have been pitted against low carb high fat (LCHF) diets, there is no instance where the low fat diet has outperformed the LCHF diet. Weight loss and risk profiles, including lipids, are all better with the LCHF. It’s been a knockout in every fight so far.
  • Sort Of: Salt raises blood pressure simply by increasing blood volume.  Equally, low salt is a risk for insulin resistance. Anyone who has ever completed a well formulated LCHF diet is aware of the importance of salt supplementation to prevent low blood pressure and cramps. The same is true for indigenous cultures who eat LCHF diets; they all add about 1.5-2.0 g salt a day.

The No’s

  • No: Where is the convincing evidence to say that saturated fat on its own is a health risk?  Here’s a recent meta-analysis of the longitudinal studies in the American Journal of Clinical Nutrition. There is no evidence of an association between saturated fat intake and cardiovascular outcomes in a combined cohort of more than 347,000 adults followed up for between 5 and 25 years.
  • No: Eat plenty of breads and cereals, preferably wholegrain, and limit your intake of high-sugar foods. Really? How about going with the more plausible mechanism for how we store fat in fat cells via raised insulin.  Insulin, you recall, is raised by carbs, even the so called healthy whole grains.  Sugar is an extra baddie – we all agree on that.  But the language is so lame, it almost condones anything other than high sugar.  Sugar and other insulin raising carbs promote hyperinsulemia, inflammation, glycation, oxidative stress, and fat storage. Because the inevitable outcome of a low fat diet is either starving yourself and keeping insulin under control that way, or a high carbohydrate diet. Either way, this regime is neither sustainable nor healthy in the long run. A low fat diet with sufficient calories for normal living is going to have to also be a high carb diet. Even if you eat lots of extra protein to avoid the extra starchy carbs, you end up with glucose anyway because excess protein will be converted, albeit inefficiently, into glucose in the liver via gluconeogenesis. 
  • No: A calorie is not a calorie.  Calories from different sources have profoundly different metabolic and hormonal effects in the body. Starchy and easily digested carbs raise insulin and insulin chronically blocks leptin. Protein raises insulin but the effect is short lasting and therefore satiating.  Fat is metabolically benign in the absence of chronically elevated insulin. This is why an “eat as much as you feel like” LCHF diet out-performs a low fat high carb diet. The way you get weight homeostasis is by controlling insulin. Perversely, the healthy food guidelines most governments push are likely to negatively affect the people who are highest risk the most; i.e. those who are less carbohydrate tolerant and therefore predisposed to excessive weight gain and insulin resistance in the presence of high carb diets. 

In the end, it looks a bit like the story about the time I was in a long distance ocean swim. The support kayaker taps me on the shoulder and says “You are going to need a change of strategy”.  “Why, I’m swimming flat out already” I reply.  “Because you haven’t made forward progress in an hour, in fact I think you are going backwards….”.  “I see, let’s talk about our options” I say.

We have to accept that we are making no progress in reducing the epidemic of obesity and chronic disease and we need to consider why. We need a discussion about our strategy.  This is the start of that discussion. We all agree that our industrialized food supply is bad but we don’t agree on how to change it and what nutrients are causing the damage.  We all mostly agree that sugar is a bad guy, but we can’t all agree that it is the effect of sugar on insulin and insulin resistance that is the problem. Yes sugar has fructose as well which has problems through other pathways. But, whether it’s loads of insulin-raising simple or complex carbs, it doesn’t matter – both need to be given the boot from the healthy food guidelines. In fact, perversely in my view, we ignore the fact that obesity is a metabolic disorder caused by any type of carb.  Sure, trans fats and the like don’t help. But let’s name the real VILLAIN here and now. It’s not saturated fat….it’s high carbs.

So what’s the answer?

  1. Stop doing nutrition research which tests one thing – the low fat dogma against the SAD. This is fundamentally bogus.
  2. Start doing research which has a start point in biology and evolution by natural selection.  That means start with some sort of paleo/primal LCHF as the “probably healthiest option” hypothesis.  Humans are omnivores = we eat plants and meat.  In human evolution, insulin was hardly ever raised excessively, and if it was, it was probably near the end of summer when man needed to pack away fat to survive the winter.
  3. Stop pretending we know everything about nutrition.  We don’t and we shouldn’t trust anyone who says they do. It’s a science in its infancy with a good deal of poor research behind it and an industry which has infiltrated research and public policy for its own benefit and not ours.
  4. Start to consider that like many other instances in human history, almost the opposite of what we have preached might be true.  Think Galileo, Hormone Replacement Therapy, causes of stomach ulcers, and dozens of times when medicine had it completely wrong.  It’s obvious that at least a few of the assumptions behind current healthy eating guidelines are bogus.

If you end up eating too many carbs in the presence of fat, no matter how paleo plant and meat based the rest of your diet, then all bets are off, you will get fat.

I’m writing this expecting to draw the wrath of colleagues, academia, government and medical and research conservatism. Hopefully first though they carefully consider points 1-4 above. What we need to start with is good science. I could be wrong, but so could you.

So let the diet wars commence; we’re in the ring and we’re ready to fight. We’re starting with the hypothesis that carbs make you fat, and that fat keeps you lean.  Bring it!

Footnote: There are typically three types of diet commonly and currently discussed; the LCHF diet, a low fat high carb diet and a moderate fat moderate carb diet (SAD). I want to reiterate that the SAD is the deadliest. A well formulated LCHF diet is not high protein, it is only adequate protein.  Low carb has nothing to do with dietary percentages.  It’s a total carb intake of <100g/day, maybe even <50g/day, or up to 150g/day for athletes. The LCHF approach is often confused by researchers and clinicians because I often see this regime criticised as either high protien, high fat, or the maount of carbohydrate quoted being far too high. Total daily carbs are what are important.

Thanks again to Helen Kilding in writing this blog

How to become a fat burning machine, lessons from athletes

Grant Schofield

Why become a fat burner?

In a previous post, Why some people stay skinny and others get fat I talked about how high carb foods lead to high insulin levels which effectively turn down, or off, your ability to burn fat. There is a longer downward spiral from years of this. But that was that post.

In this post, I want to look at exactly what you can do to turn yourself into a fat burning machine. This is not only about turning the fat burning on and creating a situation where you can drive a homeostasis for a steady and healthy weight, but is also about well-being and energy. My experience, as well as the overwhelming blogashpere and research itself, shows that an important benefit of fat adaptation is a much more stable energy level and well-being/mood.

We’ll look specifically at endurance athletes first. They want the same things that those who have problems with metabolic dysfunction want. They want to burn fat, not carbs, because humans have such a limited supply of carbs but much much bigger supplies of fat to draw upon. When athletes going long distances run out of carbs they are said “to hit the wall” or “bonk” (French for the noise your head makes when it hits the road?) So we’ll look at some of our lab results with an athlete later.

It’s not about treating carbs as evil and trying to run your body without carbs. In some ways it’s the exact opposite – it’s about sparing the glucose you do have. It’s about getting your body to do what it is designed to do under usual evolutionary conditions – burn fat and have enough energy to move all day and/or make short intense bursts. Becoming an efficient fat burner allows you to do just this.

Carb burners v Fat burners

If your metabolism is set up to predominately burn carbs, then you’ll most likely have many more highs and lows throughout the day energy wise. I call the lows “falling off the glucose cliff”. That’s when your glucose dependent brain cries out for more fuel – in the form of simple carbs usually. The cycle continues. If that’s you, then this blog could change your life for the better!

There are many plausible or proven health benefits here to. There is the obvious one of easily being able to control your weight. But far beyond that is reducing the damage high sugar, and high insulin, and sugar burning (glycolysis) do in your body. All of these are inflammatory and cause oxidative stress. These are the causative mechanisms behind chronic disease development including heart disease and stroke, diabetes, cancer, and brain (dys)function.

Fat burning in endurance exercise

One lab-based method we use to measure fat burning vs carb burning is the respiratory exchange ration (RER), also known as the respiratory quotient. This is the ratio between the amount of carbon dioxide exhaled and oxygen inhaled, which provides an indication of which substrate (fat, carbohydrate or a mix) is being used for fuel. We do this using our breath by breath gas analysis system in our Metabolic and Exercise Science Clinic at the Human Potential Centre at AUT Millennium Campus.

The RER varies between 0.7 (100% fat burning) through to ≥1.0 (100% Carb burning). A ratio of 0.85 has been labelled the metabolic efficiency point, when the body burns half of each. We try to determine what exercise output can be maintained for half and half. Bear in mind that everyone will eventually burn 100% carbs if the exercise is intense enough, but the higher the intensity at which fat is still the predominant energy source the better. However, what we are most concerned with is the ability to burn fat at rest and at lower to moderate intensities of exercise. This is great for weight loss. It’s great for health. But it’s also great if you are an athlete trying to do longer distance events like the Ironman triathlon.

We recently had a high level triathlete in our lab. We measured his RER before and after a 10 week training block going into this year’s Ironman NZ. We also transferred him to a low carb high fat (LCHF) diet for the period of that training. He was training about 20 hours a week and came in to the 10 week block relatively fit, albeit slightly heavier than he wished.

Some stats:

  1. Start weight 86 kg, post weight 78 kg. Good weight loss while reporting eating until full. No deprivation of food or calories if needed. Reduced calorie consumption on long training sessions. Few if any gels or sports drinks.
  2. Pre RER @ 270 W bike = 0.93, post RER @300 W = 0.82. This translates to a change in fat utilization from 23% of fuel to 60% of fuel at the same power output, for a lighter overall weight (power per kilo was also increased).
  3. Metabolic efficiency point (50/50 fuel use) improved from 180 W to 300 W. This shows the massive increase in efficiency we saw with a switch to a LCHF diet.

If you know anything about endurance training and racing then you’ll know that these results are outstanding. To the point of being spectacular. The limiting factor in longer races is not maximal output, but how fast you can go while conserving muscle and liver glycogen (carbs). You need to maximize your fat burning and preserve your very limited supply of carbs as much as possible.

Most athletes try to get around this problem by eating extra carbs during training and racing. This can work to an extent, but perversely raises insulin and shuts down your body’s ability to burn fat. It’s almost impossible to eat and digest enough carbohydrate to actually race these events well. You need a good degree of fat burning.

Anyway, this illustrates what can be achieved with a LCHF diet; good, effortless weight loss and spectacular performance gains.

If you’re not an athlete, and I’m assuming most of you are not, then the same principles still apply. We can hook you up to the gas analysis system and determine your “metabolic efficiency” at rest. We can assess just how much of a carb burner you are and we can track your progress if you decide to become a fat burning machine through a LCHF diet.

Fat adaptation v ketosis

There’s a special type of low carbohydrate diet called a ketotic diet. I want to explore that in the next post. Stay tuned.


Thanks to Helen Kilding for her help with this blog

Why some people stay skinny and others get fat

Obesity

What I want to put forward today is that there is evidence for two distinct modes of human metabolic state. One is being “fat adapted”. That is, a state where the hormone insulin is well controlled and the body is able to access its stores of fat as a primary source of fuel. This, I contend, is the normal human state. The complex interaction of cells, hormones, enzymes and much much more is in balance.  We homeostatically maintain a desirable body weight by self-regulating inputs and outputs. In this state, if we over-eat, we will compensate and burn it off.  And vice versa if we under-eat. The mechanisms are complex and not all are well understood.  It’s at least a great starting hypothesis.  Good science is  needed to nail down the whole mechanism but putting together animal and human evidence points to this.  This is fundamentally why the “calorie is a calorie” dogma that has plagued nutritional science for the past 40 years is wrong.

When you are “fat adapted” you can easily utilise fat, you have less craving for simple carbs and, most importantly, insulin is well controlled.

However, when you continually eat large amounts of carbohydrates, especially simple refined carbs, then the second mode of human metabolic state results and the body becomes what I have decided to term “metabolically dysregulated”. Others have used the term “metabolically deranged”, but I find that a little too emotional!  The mechanism is simplified as follows:

  1. The body has to continually deal with large loads of dietary carbs.
  2. It does this by producing insulin, a storage hormone which shuts off the ability to burn fat as a fuel source and get carbs into cells. Some will go into muscle cells (especially in an active individual); some goes into the liver; but if the muscle cells and liver are full, which they often are because they have a limited capacity and people often expend very little energy, then the carbs are stored in fat cells.  That’s the basic mechanism for the storing of fat.  Insulin also drives extra fat into fat cells too. That’s it. Simple.  Insulin makes fats cells get bigger. Without a rise in insulin, there is no easy mechanism for this process.
  3. Insulin also blocks an important hunger hormone called leptin. Leptin is secreted by fat cells and signals to the hypothalamus in the brain that the body is not starving. By blocking this hormone, insulin is effectively block the “off switch” for hunger so we over-eat.
  4. Insulin also down-regulates (the process by which a cell decreases the quantity of a cellular component) the pleasure hormone dopamine’s receptors in the brine. This is what gives simple carbs their addictive quality.
  5. Insulin also down-regulates sympathetic nervous system activity resulting in a reduced propensity to expend energy through both incidental and purposeful physical activity.
  6. It’s a downward spiral as you get fatter and less regulated and continue to bombard the body with large doses of dietary carbs. You become more and more insulin resistant, both at the muscle and liver cell level.  In other words, you need more and more insulin to get the carbs into the cells. Insulin is permanently high.  So your cells become more existent.  You are always storing fat, never burning it and a state of hyperinsulemia (high insulin) ensues, even when you are not eating. You become fatter, especially around your central area (visceral obesity), which drives more inflammation and increased insulin resistance.  Oh boy….!
  7. Eventually, the beta cells in the pancreas which produce insulin start to fail and you can’t manage your blood sugar levels at all. That’s Diabetes. Constantly high blood sugar is toxic to all parts of the body it touches, and it touches everything of course.

So that is what I call becoming metabolically dysregulated.  It is caused by lots of simple dietary carbs. It’s a pandemic.  It’s because we have a food supply choked full of processed carbs. And even worse, our medical advice is to go low fat. Low fat, by definition, will mean high carb for the body.  More on why in later blogs.

So that’s the dietary choice you have in my view. Eat whole unprocessed foods; low carb, leafy vegetables, moderate protein, high fat and you will avoid the insulin peaks and eventual dysregulation described above.  Eat the carbs, send insulin way up and suffer the consequences of metabolic dysregulation. Fat burning shuts down,energy out shuts down.  Fat storage goes up.  Because energy out is synonymous with quality of life, you feel crap. Being the best you can be has a central requirement of being metabolically well regulated.  That’s why I am so interested in nutrition.

Thanks to Helen Kilding for her help with this blog

Be the best you can be

photo

(pic: the entrance to AUT Millenium where I work)

I’ve wanted to start a blog for quite some time now. The trick is to get the technical skills together well enough to actually know how to run one and do it regularly. Well, I’m just about there.

What will I blog about?

I am really interested in the science of how we can be the best we can be. This crosses disciplines such as biology, medicine, pubic health, and productivity management. The cornerstones are nutrition, exercise, sleep, neuroscience, psychology and well-being. I’ll be covering these topics under the broad heading of the Science of Human Potential (the name of this blog).

I’ve been interested in human health and performance for my whole career. I started in psychology then into sport and exercise psychology, then into public health especially physical activity then obesity.

There have been some twists and turns along the way which might help to give a view of why I do what I do and where it can go.

About me

Sport and exercise has always been a massive part of my life. From an early age I played rugby union, learned to sail and race, and eventually ended up in the high school rowing squad. Rowing at my high school had no room for anything but high performance. So I was introduced to this at age 13. From there we won national championships most years. The combination of the sheer physicality of the sport and the team work and individual excellence required both mentally and physically really defined my teenage years and who I could become as an adult.

Being fit and involved in some sort of high performance activity has been part of my life since then.

I finished bachelors, Honors, and doctoral degrees in psychology at the University of Auckland by 1994. At the same time I had got into triathlon as a sport. I ended up racing semi-professionally. That’s code for “was never quite fast enough to earn a decent living, so had to supplement prize money income by working“. In the end I raced professionally in several world championships in long course triathlon, ironman and duathlon. That was great fun, and the skills and work ethic I have learned from triathlon are important to me.

The extra benefits from the high performance sport world, especially triathlo,n include:

  • I met my wife Louise because of triathlon. She ended up also as a professional triathlete, a better athlete than me. We’ve been married since 1995 and have three boys – Sam, Jackson and Daniel. Louise also started Vitality Works, a workplace health company acquired by Sanitarium in 2012. Vitality Works has allowed both of us to benefit from a huge amount of professional and personal development in health and well-being.
  • I figured out early that a high performance life is just as much work as a low performance life, so you may as well take the high performance life. It just requires a bit more work up front, but frankly you avoid work later and you get more choices.
  • I have the skills to stay fit and enjoy maximizing my biology for my own personal peak performance.
  • I still get to compete at a reasonable level in triathlon and running. This is cool because the age group triathlon and running groups are really fun, and you get to hang out with people of a similar performance, health, and happiness mindset.

My academic career began with part-time teaching in the Psychology Department at The University of Auckland during my PhD tenure. I moved to Australia (Central Queensland University in Rockhampton) and worked in the School of Psychology there for nearly 10 years. Most of our spare time then was dedicated to triathlon training and racing with Louise. I wasn’t going fast or far in the academic world at that point. Enter Kerry Mummery.

Kerry Mummery is now the Dean of Physical Education at the University of Alberta. He really mentored and started me on the journey to becoming a decent academic. We worked on several physical activity and health projects together. The most notable was 10,000 Steps. This started as a whole community project and morphed into a nationwide program which is still running successfully today.

This was the entrance into public health proper for me. I started at AUT in 2003 after the birth of Jackson our second son. Back in Auckland and into a new country with plenty to do. That’s when things really took off. I had the good fortune to have several great staff members and PhD students under my guidance. Almost all of these are still with me.

The highlights in the last decade are:

  • Working with dozens of talented doctoral and masters thesis students
  • Being highly successful in obtaining research grants and funding. This is the life of an academic and you live and die by this success. We are up over $20 million in funding.
  • A solid and respectable publication record. Ditto above. Important for gauging success. But by itself is unlikely to put much of a dent in the universe.
  • Being involved in Vitality Works. This has put a dent in the universe and allowed me to develop more formally into peak performance, well being and neuroscience.
  • Being the youngest full professor around for a while. That wore off as I aged!
  • Moving our work beyond physical activity into obesity, well-being, productivity, and nutrition/weight loss. Most recently the work we are starting in metabolic efficiency and weight is likely to put the biggest dent in the world.
  • Starting the Centre for Physical Activity and Nutrition and eventually morphing that into the Human Potential Centre at the new Millennium Campus.

So that’s where I’m at. Where I want to go now, and with this blog, is to explore the science behind what helps us “be the best we can be.” It’s an emerging and multidisciplinary science. Let’s go!