Running on Fat …

Back in my marathon days (30+ years ago) I remember reading a prediction that it wouldn’t be long before women were beating the men over the magic distance of 26.2 miles. The logic was very simple, fat is an excellent fuel, fit women athletes carry more fat than fit men athletes therefore women would be better over long distances than men once they matched the men in training.

So far it hasn’t happened, fastest man – Eliud Kipchoge of Kenya 2:01:39 fastest woman Brigid Kosgei also from Kenya 2:14:04. Getting on for 10% slower.

At about 9 calories per gram fat is an excellent fuel trouble is for endurance sports the body is very happy burning glucose and glycogen even though they pack only 4 calories per gram. Stores of glycogen exist in muscle and in the liver amounting to about 600 grams. In ball park figures that’s about 2400 calories for a marathon requiring about 2600. A runner can expect to absorb 50 to 60 grams of glucose from the gut per hour which easily makes up the shortfall.

So fat burning doesn’t really get into the equation during an elite marathon. If it did even the thinnest male athlete has enough fat to go the distance.

Glycogen is king. Glycogen replenishment happens faster after a carbohydrate rich meal. What are the implications for the athlete following a keto diet? Depends who you ask. According to Harvey, Holcomb & Kolwicz the keto athlete is operating at a distinct disadvantage although it is an excellent diet for weight loss.

Dr Caryn Zinn on the other hand is more optimistic …

while Professor Asker Jeukendrup sums up what is known but leaves the question open. That article is well worth reading.

Fat oxidation rates are on average 0.5 grams per min at the optimal exercise intensity. So in order to oxidise 1kg of fat mass, more than 33 hours of exercise is required! Walking or running exercise around 50-65% of VO2max seems to be an optimal intensity to oxidise fat. The duration of exercise, however, plays a crucial role, with an increasing importance of fat oxidation with longer exercise.

There is no doubt that the reforming couch potato can successfully lose weight and burn fat at moderate rates of exercise on a keto diet. Fat around the middle is as much a handicap as lead in the saddle bags. VO2max is the upper limit of your ability to burn fuel a good measure of your fitness. More precisely it’s milliliters of oxygen consumed in one minute, per kilogram of body weight (mL/kg/min) at sustained maximum effort. In other words get the kilograms down and the VO2max goes up without any extra training.

Progress Report …

We are two weeks into the Low Carb diet. Gayle has been cooking up a storm. Some of the food is less than exciting but most is delicious. Some is quite exceptional given the inclusion of previously shunned fats.

We haven’t been able to bring ourselves to eat dead animals so have to be thoughtful about our protein, eggs and cheese are in after that it’s tofu and nuts. Ground linseeds help with the omega 3s. Vitamin B12 comes from a pill.

I was losing weight before starting the diet. Three kilograms in the three months since I bought the bike. Two more kilograms have gone in the past two weeks along with 2 inches off the belly. No cravings, hunger satisfied. Not a calorie has been counted. I’m drinking a lot and peeing a lot, sure signs of ketosis. My confidence is high.

It feels as though athletic performance has suffered a bit, perhaps more for Gayle than me. We have been able to keep up a pretty high volume (by our standards anyway) 343 km in the past 14 days. I skipped this week’s long ride in favour of a more modest distance. I think we are getting through that now as we start to burn fat as our energy source.

Every diet that I’ve tried has worked … for a while. The promise from this one is that it will go on working. We will see.

Low Carb High Fat …

Get ready to read a lot of packets and do a lot of home cooking.

What’s in?

Meat, seafood, eggs, full-fat dairy, above ground vegetables, nuts, avocados and in moderation dark chocolate, berries and dry wine.

What’s out?

The bottom layer of the food pyramid!

Starches (including bread), sweets, processed meats, low fat or sweetened dairy, high sugar fruits.

Orthodoxy would have it otherwise …

The acceptable macronutrient distribution ranges (AMDR) are 45–65% of your daily calories from carbs, 20–35% from fats and 10–35% from protein. (

Ancel Keys is a goliath of the orthodoxy. His rather sketchy epidemiologic research into diet and heart disease pointed the finger at saturated fat as the cause. In 1977 a US Senate Committee issued the Dietary Goals for the United States which became the Dietary Guidelines for Americans. The American Heart Association was on board but Philip Handler, President of the National Academy of Science had this to say,

What right has the federal government to propose that the American people conduct a vast nutritional experiment, with themselves as subjects, on the face of so little evidence?

Heart disease hasn’t gone away, obesity and type 2 diabetes have soared.

There is a great deal of inertia in that orthodoxy but it is slowly crumbling under the onslaught of evidence. Ain’t nothin’ wrong with getting your calories from fat. It satisfies hunger without sending insulin levels through the roof. For some of us it may be the best option, at least for a while.

The way to plan your meals is simple. First pick your protein source aiming for roughly 1.5 grams per kilogram of your reference weight (life tables previous post). Next add a couple of serves of above ground veggies. Finally some fat stuff like avacado or nuts.

So that could be a chunk of meat with the fat on and two veg. Sounds just like the meals my mother used to cook and there weren’t many fat kids around back then.

There are any number of resources online and a shelf-full of cook books at the shop. Look for keto or LCHF, checkout Low Carb Australia on Youtube.

It is powerful stuff and it will change your biochemistry. If you are on anti-hypertensives, anti-diabetic agents including insulin, pregnant or breast feeding medical supervision is needed.


Picking and Choosing ..

Chances are the short term goal is weight loss but for all of us the long term goal has to be a healthy diet. What would be the properties of an ideal diet? For starters as it were …

  • macronutrients -protein, fat, carbohydrate in the right proportions
  • micronutrients
  • taste good
  • hunger satisfied
  • ill effects avoided
  • weight maintained

I would love to have you refine that outline, hit the comments.

The first problem is to know what the ideal balance of the big three would be. A varied diet of whole foods will supply the micronutrients unless of course you decide to leave out the dead animals in which case some supplementation is needed. Most food tastes good. Get thee behind me hunger. Ill effects are everywhere, beware the FODMAPS, gluten, emulsifiers maybe everything. And the holy grail – weight.

Next thread a passage through the evangelical adherents pushing various species of diet with missionary zeal.

Should we aim for the diet of our hunter gatherer forebears, a wholegrain version of the agricultural diet or is the industrial diet the go? Is it really that hard?

Here now is the fortune cooky guide to dieting …

What do you need to achieve? If you are at peace with your diet and your weight you are doing fine. Enjoy. By at peace I don’t mean defiantly refusing to be fat shamed. Do think of the future and keep off the processed foods. I see real foods and home cooking in your very long future.

Two or three kilos too many? Is that all? I envy you. Any of the weight loss diets will shift that. Transition to a whole food regime add some exercise to stay on track. The warning has been sounded though. Step on the scales once a week.

Under weight? Especially in the older age group … have a chat with your doctor.

And now it’s all about me. And maybe you.

The fat is packed around the viscera. The tape measure has spoken. Business as usual means a descent into diabetes, hypertension, ischaemic heart disease and kids enjoying their inheritance too young to manage it wisely. Why surrender?

The body can burn glucose or it can burn fat. When it’s well it can burn a mixture but generally one or the other . When there is insulin resistance fasting insulin levels stay high. Fat cannot be metabolised. Your diet is relatively high in carbohydrate. On any day when calories in equals calories out your weight stays the same. On days when you are behind on the intake your brain tells you to catch up, insistently. You do. Go over on the calories and you lay down some fat. Your weight can only ratchet up. Insulin resistance is in the driving seat.

So lets burn fat and the only way to do that is to curtail the carbs.

LCHF stands for low carb high fat. Protein stays mid range at or about 1.5 grams per kg of reference weight. (That’s the weight from the life insurance tables not the weight you are now). The pancreas will not be working so hard, gluconeogenesis will top up the glucose, the brain will be running on ketones, birds will sing and the sky will be blue.

Ideal Weight Tables

Metropolitan Life Insurance 1959.

Metabolic Syndrome …

  • High blood pressure
  • High blood glucose
  • Excess fat around the waist
  • Raised cholesterol
  • Raised triglycerides

If you have any three of these you are in the gun. Your risks of type 2 diabetes and heart disease are higher.

Syndromes are not diseases they are clusters of signs that have a high chance of occurring together. Presumably there is an underlying cause but it may not be obvious. In this instance, though, your money would be pretty safe on insulin resistance.

According to the Mayo Clinic website if you have any one of these it’s time to see your doctor. They go on to say …

  • Metabolic syndrome is increasingly common, and up to one-third of U.S. adults have it. If you have metabolic syndrome or any of its components, aggressive lifestyle changes can delay or even prevent the development of serious health problems.

My score is one out of five. I have seen the doctor. The aggressive life style change is underway. You didn’t think I was just writing this for your benefit, did you?

When I look in the bathroom mirror my belly doesn’t look too bad. If I turn my head 90 degrees to the right the awful truth is revealed in a mirror in the adjacent walk-in robe. I guess that’s why friends and the ever solicitous Gayle were so keen to get me on the bike. I’m sure they didn’t expect an instant cycling tragic.

I googled “ideal girth” and got the shock of my life. I was quite competitive though. That’s something you can checkout for yourself or leave a mystery.

I then googled “ideal waist size” and found what I wanted. Then I found a tape measure. And then I contemplated my future.

A man’s waist should be no greater than 40 inches or 102 cm. A woman’s should be no more than 35 inches or 89 cm. Oh, the shame … 44 inches.

Armed with that and your height you can get a reasonably close estimate of your percentage of body fat. The theory is <Here> a calculator can be found <Here>. It is a better measure than BMI which suffers from a number of deficiencies. Arnold Schwarzenegger at his peak had a BMI of 34 (or thereabouts, accounts vary). That puts him securely in the obese range (30 – 39.9). Doesn’t look it …

Actually my BMI ain’t that different. Should be OK.

Well no. It’s time for exercise and diet. Which diet?

Why Surrender …

Diabetes comes in several flavours. Diabetes mellitus is the sweet one – the problem is in the pancreas, diabetes insipidus is a less famous alternative that has it’s origin in the pituitary gland.

At university I learnt a very neat summary that I could regurgitate at exam time, “Diabetes mellitus is characterised by polydipsia, polyurea, ketosis, coma and death”.

Polydipsia, polyuria are excessive drinking and excessive peeing. They are the features that make the disease a diabetes which is a name that comes from the Greek meaning passing through or a siphon. Mellitus is from the Latin, why be consistent, meaning sweet. And yes, back in the day the doctor had to taste the urine to make the diagnosis, or at least his apprentice did.

Type 1 diabetes (mellitus) usually has its origin in childhood. It’s due to an autoimmune attack on the cells that make insulin in the pancreas. Death can be averted by regular injections of insulin, a treatment that was first used in 1922.

What I didn’t learn about at university was the work of Frederick Allen. He pioneered the treatment of diabetes with a low carbohydrate diet. The link that describes Allen’s work has this to say …

Allen’s diet was far from a cure. It essentially brought people with severe diabetes to the brink of starvation in order to control the disease.

The brink of starvation, really? Fat and protein are essential nutrients and are as calorie rich as carbohydrate. The body can make as much glucose as it needs from these sources by the process of gluconeogenesis. Nor is insulin a cure it’s a lifetime’s treatment. A lifetime in which even well controlled diabetics face complications like blindness, heart disease and severe vascular problems. Carbohydrate is not an essential nutrient although it would be almost impossible to dream up a diet that was entirely carbohydrate free. Our Frederick may have been on to something that the addition of lower doses of insulin could have made even better.

Now please don’t take anything that I’m saying here as individual advice. A low carb diet will bring down blood glucose and blood pressure. If you’re on antidiabetic agents or antihypertensives this could put you in more than a spot of bother. If you’re on medication and considering a low carb diet a discussion with your doctor is essential.

For adults with pre-diabetes or as yet on oral antidiabetic agents a vigorous fight back appeals to me far more than a surrender.

In the last post I mentioned the Diabetes Australia web site. If you search the site you can find their statement on low carb diets. For type 1 diabetes the verdict is unproven, more studies needed. For type 2 they have this to say …

In summary, this research indicates that lower carb diets are more effective at reducing blood glucose levels in the short term (three to six months) than higher carb diets and appear to be at least as effective as higher carb diets for long term blood glucose management (12-24 months) and weight loss.

So why are they steering people away from it?



Diet and the Older Athlete …

I’m losing weight faster than you because I’m busy doing stuff not sitting reading about nutrition.                           Gayle.

The story so far … overweight, unfit, somewhat depressed old dude starts cycling in an attempt to reduce his weight and improve his health. Finds it exhilarating and becomes obsessed.

I’m no stranger to losing weight. I’m actually quite good at it. It’s just that I’m even better at gaining it. It’s practically an annual cycle. Weight loss diets work, the kilos drop off, the will power is reinforced by the success but the hunger mounts, the weight loss stalls and I crack. Six weeks in, six kilos down, six months in back to square one. At least the annual average is slightly lower and there are some benefits that last a while even though the weight has returned.

The last couple of diets have been 5/2 style exercises. The first was very effective. I ate nothing two separate days in the week and my normal diet the other five. Weight loss was quick. It slowed after about 7 kg. I suspect the main reason was increasing my intake on the eating days led to a stalemate. The regime collapsed on a holiday in Japan and I didn’t find the enthusiasm to resume.

The weight crept back up. A year later I tried again. This time I ate a small evening meal on the fast days. It was not quite as effective but the rebound was.

A wise man once said “Don’t make any change to your diet that you’re not prepared to make permanent”. That was Ogie Shaw. What he recommended instead was an exercise regime well outside my capabilities physically and not in the least appealing. Nonetheless the advice is good. Lets make it a lifestyle diet not a weight loss diet.

So what should the older cyclist eat?

Stuffed if I know, but there are several places to go for advice. Quickly categorised these are

  • Doctors and dieticians
  • Government issued dietary guidelines
  • Cycling mythology
  • Medical literature
  • Dr Google
  • Fads, quacks and influencers

There is a lot of overlap in these broad groups, the professionals may reinforce the dietary guidelines and you’d hope that they occasionally delve into the literature. However there is a subset of doctors who take issue with the guidelines and they’ve certainly found literature to support their case – ask Dr Google about Low Carb.

Cycling specific advice is interesting. As always the brains are attracted to the money. In cycling the money is with national bodies hoping to bring home gold medals. Top exercise physiologists and coaches are working with elite riders with peak performance as their goal. The result is an extraordinarily high carbohydrate intake.  Peak performance in a brief competitive career may not equate to long term health. I am not expecting to win any gold medals so I will not be sucking on any gels, my liver and pancreas deserve better and I’m very fond of my teeth.

Back in my marathon running days I knew that long runs build stamina, patience and experience but could never fit in as many as I would have liked. enough time to run many long distances in training. I would find myself increasing the length of my sessions as the big day approached aiming to do one 20 miler a week or so before the race. At the same time I was very conscious that being lighter was being faster. Let me tell you from experience that calorie restriction and an increasing workload do not sit well together.

So, while Gayle has been out chopping down trees and replacing fences I have been doing some research. Stay tuned.