Completing the trine: vive la différence!

First, the obligatory picture of Hannah Spearritt :-)

Women have a harder time losing weight than men. Women retain water more than men for hormonal reasons, but a factor that's overlooked is that, on average, healthy women have higher body-fat percentages than healthy men. This is because women have babies and men don't. Who knew? On the plus side, women produce more DHA than men.

Why should having higher body-fat percentages make a difference to weight loss? See What is the required energy deficit per unit weight loss? The energy deficit required to lose 1lb of body-weight increases with increasing body-fat percentage. It's rarely 3,500kcals per lb.

If you really love mathematics, see The Dynamics of Human Body Weight Change.

From the above paper:- ΔU = ΔQ - ΔW

where ΔU is the change in stored energy in the body, ΔQ is a change in energy input or intake, and ΔW is a change in energy output or expenditure. This is the Energy Balance Equation. As I said back in Back to black, CIAB, pharmaceutical drug deficiencies & nerds.

Where body weight is concerned, calories count (but don't bother trying to count them).
Where body composition is concerned, partitioning counts.
Where health is concerned, macronutrient ratios, EFAs, minerals, vitamins & lifestyles count.

N.B. Poor health can adversely affect body weight and/or body composition, by increasing appetite and/or by adversely affecting partitioning.

Use and abuse of technology and energy.

Take a look at the picture below.

Samsung Galaxy S vs iPhone 4

Using technology and energy: Oil, ores, minerals and sand are turned into plastics, metals, ceramics and glasses. The latter cost and are worth more than the former. Using more technology and energy: Plastics, metals, ceramics and glasses are turned into smart-phones, computers, TV sets, cars, planes, musical instruments, w.h.y. The latter cost and are worth more than the former. Creating gizmos creates wealth and increases value.

Take a look at the picture below (hat-tip to Beth Mazur).

You know who is really leaning in? Little Debbie. We have enough crap to eat. Dial it back a little.

Using technology and energy: Produce are turned into crap-in-a-bag/box/bottle (CIAB). The latter cost more than the former but are worth less, as nutritional value has been reduced. Creating CIAB creates wealth but decreases value.

I would like there to be more production of gizmos and less production of CIAB.

Everyone is Different, Part 2.

Cont'd from We are not all the same.

A long, long time ago...


I learned that Everyone is Different, thanks to a study by Julia H. Goedecke, Alan St Clair Gibson, Liesl Grobler, Malcolm Collins, Timothy D. Noakes and Estelle V. Lambert.

Well, stone the flamin' crows! Timothy D. Noakes' name just popped up in Alan Aragon's article 2013 NSCA Personal Trainers Conference: Looking Back at my Debate with Dr. Jeff Volek. Dr. Noakes has had problems with his blood glucose level and has adopted a very-low-carb/ketogenic diet.

What also caught my eye in Alan Aragon's article was (Note: TTE = Time To Exhaustion):-
"However, the authors’ conclusion is misleading since 2 of the 5 subjects experienced substantial drops in endurance capacity (48 and 51-minute declines in TTE, to be exact). One of the subjects had a freakishly high 84-minute increase in TTE, while the other increases were 3 and 30 minutes."

I expect that the subjects with 84 and 30 minute increases in TTE would be praising ketogenic diets, whereas the subjects with 48 and 51 minute declines in TTE would be cursing them and the subject with 3 minutes increase would be "Meh". Vive la difference!

Also note that sprint capability...remained constrained during the period of carbohydrate restriction. As mentioned in It's all in a day's work (as measured in Joules), exercise above a certain intensity (~85%VO2max) burns significant amounts of carbs, no matter how fat-adapted someone is.

Cont'd on Everyone is Different, Part 3.

It’s the Calories, Stupid.

I thought I'd mark my return to blogging by taking the piss out of a certain Diet Doctor for his post It’s the Insulin, Stupid, who takes (and tweaks) Fig 7A from Hyperinsulinemia Drives Diet-Induced Obesity Independently of Brain Insulin Production.

At first glance, Fig 7A looks like a CIH believer's dream come true (apart from the words "High Fat Diet").

Hyperinsulinemia → Obesity.

Obesity is caused by too much insulin. Game, Set and Match to insulin.

Not so fast! Let's take a look at the rest of Fig 7.

Figure 7. Revisiting the Current Model of Obesity and Type 2 Diabetes(A) The most widely accepted model of the pathogenesis of obesity and type 2 diabetes posits that a high-fat diet leads to obesity and insulin resistance (there is debate about the relative order and causality of these). In this widely held view, insulin resistance then leads to hyperinsulinemia, which is followed by β cell exhaustion, and then type 2 diabetes. The accepted model is incompatible with our results that put the insulin hypersecretion genetically upstream of obesity.(B) Our data support a model whereby insulin levels must be kept low to maintain energy expenditure in white adipose tissue via the expression of Ucp1. Our data do not address the order of subsequent events after obesity (outside the yellow box), such as insulin resistance and/or type 2 diabetes, since they were not observed in our studies. In other words, the effects of insulin gene dosage on obesity are independent of sustained changes in glucose homeostasis or insulin resistance.

↑ Peripheral Hyperinsulinemia → ↓ Uncoupling Proteins (WAT) → ↓ Energy Expenditure → ↑ Obesity.

Obesity is caused by a reduction in energy expenditure. Game, Set and Match to The Energy Balance Equation. It’s the Calories, Stupid. In the mice in this study, energy expenditure is strongly influenced by insulin levels. In humans, not a lot. In humans, insulin can act as a stimulant and as a sedative.

I'm not an insulin denier as is obvious from my other blog posts. I'm still controlling my carbohydrate intake.
I'm not a food reward denier and I've been using food reward principles to lose some more weight.

The above post will probably annoy some people. Before wasting your time writing a comment, please note my Moderation Policy.

It's all in a day's work (as measured in Joules) Part 2.

Are you as aerobically-fit as this bloke?

Emmanuel Mutai made it a Kenyan double after winning the Virgin London Marathon in a new course record. Mutai's time of 2:04.38, beats the previous best of 2:05.10 set by Samuel Wanjiru in 2009 and also the fifth-fastest time ever.

I'll take it that's a "no", then.

Elite marathon runners have optimised their metabolisms to use the minimum possible amount of muscle glycogen as fuel. Muscle glycogen storage is limited to ~1,680kcals-worth (~420g of carb)*.
Supercompensation (depletion followed by 3 days of carb-loading) can increase this figure to ~720g*.
Fat storage can amount to ~35,000kcals-worth (~10lb of fat), even in a skinny Kenyan like Mutai.

A blogger called Thor Falk took the data from It's all in a day's work (as measured in Joules) and plotted it as a graph in Fat vs carb burning – a N=1 chart. Here's the graph:-

Even a super-fit Kenyan like Mutai burns some carbs when running at ~12.5 miles per hour. The less fit that somebody is, the more the first corner in the blue plot moves down and to the left. This results in more carbs being burned at energy consumption levels more than the first corner. This depletes muscle glycogen stores faster, resulting in "hitting the wall" (running out of muscle glycogen) sooner.

Muscles that are depleted of glycogen are more insulin-sensitive than muscles that have more glycogen, therefore the less aerobically-fit somebody is, the sooner their muscles become insulin-sensitive when they exercise.

*Assuming 20kg of muscle (Lore of Running P104)

It's all in a day's work (as measured in Joules)

The title is from the "Physics Man" sketch on The Now Show. Work is another word for energy and there are two different units for it.

The calorie (cal) is the amount of energy required to heat 1g of water by 1°C. This is a tiny amount of energy. The dietary Calorie (Cal) = 1,000cal = 1kcal.

The Joule (J) is the SI unit of energy. 1J = 1kg*m^2/s^2.
1Joule/sec = 1Watt (W).

1kcal = 4.186kJ.

At rest, an average human body uses ~1kcal/min = ~4,186J/min = ~69.8J/sec = ~69.8W.

The brain uses ~5g of glucose/hour = 18.75kcal/hour (1g of carb = 3.75kcals, usually rounded-up to 4) = 78487.5J/hour = ~21.8W.

The heart uses ~10W. The liver, kidneys, gut and lungs run continuously so they use energy all of the time.

Skeletal muscle uses a variable amount of energy using a variable proportion of fuels, depending on what you're doing with it. A chap called Steve sent me a spreadsheet of results in 2004 when he underwent a metabolic test on a stationary bike while breathing through a respiratory gas analyser, which calculated kcals burned and fuel usage by measuring Respiratory Exchange Ratio (RER).

At~1kcal/min (resting), he burned ~95% from fat (~0.11g/min), ~5% from carbs (~0.01g/min).
At 2kcal/min (12% max), he burned 100% from fat (0.22g/min), 0% from carbs (0.00g/min).
At 3kcal/min (18% max), he burned 100% from fat (0.33g/min), 0% from carbs (0.00g/min).
At 4kcal/min (24% max), he burned 99% from fat (0.44g/min), 1% from carbs (0.01g/min).
At 5kcal/min (29% max), he burned 48% from fat (0.27g/min), 52% from carbs (0.69g/min).
At 6kcal/min (35% max), he burned 62% from fat (0.41g/min), 38% from carbs (0.61g/min).
At 7kcal/min (41% max), he burned 58% from fat (0.45g/min), 42% from carbs (0.78g/min).
At 8kcal/min (47% max), he burned 46% from fat (0.41g/min), 54% from carbs (1.15g/min).
At 9kcal/min (53% max), he burned 42% from fat (0.53g/min), 58% from carbs (1.39g/min).
At 10kcal/min (59% max), he burned 44% from fat (0.49g/min), 56% from carbs (1.49g/min).
At 11kcal/min (65% max), he burned 38% from fat (0.46g/min), 62% from carbs (1.82g/min).
At 12kcal/min (71% max), he burned 41% from fat (0.55g/min), 59% from carbs (1.89g/min).
At 13kcal/min (76% max), he burned 37% from fat (0.53g/min), 63% from carbs (2.18g/min).
At 14kcal/min (82% max), he burned 30% from fat (0.47g/min), 70% from carbs (2.61g/min).
At 15kcal/min (88% max), he burned 14% from fat (0.23g/min), 86% from carbs (3.44g/min).
At 16kcal/min (94% max), he burned 0% from fat (0.00g/min), 100% from carbs (4.27g/min).
At 17kcal/min (100% max), he burned 0% from fat (0.00g/min), 100% from carbs (4.53g/min).

Over a wide range of intensities, the number of grams of fat Steve burned/min was fairly constant.

Note that 17kcals/min = 1186.6W, or 1.19kW. This level can be maintained for only a few seconds, as carbs are burned both aerobically and anaerobically, which exhausts PhosphoCreatine stores in muscles and also causes an accumulation of lactate in muscles. See Why do muscles hurt after exercise?

Muscle mass is very metabolically-active compared to fat mass, as one pound of fat mass burns only about 2kcal a day. See also Dissecting the Energy Needs of the Body – Research Review

Here's another Physics Man.

Why counting Calories and weighing yourself regularly can be a waste of time.

To lose weight, eat fewer Calories than you burn. Sounds fairly straightforward, doesn't it? Well, all sorts of things can mess up this simple maxim.

What is a Calorie?

One dietary Calorie (Cal) is 1000calories, or 1kcal for short. A calorie (cal) is the amount of energy required to heat 1g (1mL) of water by 1degree C. As 1cal is a tiny amount of energy, kcal is commonly used. I prefer to use kcal rather than Cal, as the first word in a sentence is always capitalised which could cause confusion.

The SI unit of energy is the Joule (J) and is the amount of energy required to lift a 1kg weight 1m into the air. As 1J is also a tiny amount of energy, kJ is commonly used. There are 4.186kJ in 1kcal.

Why counting Calories can be a waste of time.

1) When the label on a packet of food states that the food contains Xkcals or YkJ, the number isn't accurate. See Food Composition Analysis and its Implications for Dietary Planning.

2) Most people are hopeless at judging portion sizes, even when using a measuring spoon! Watch the following video made by Leigh Peele called Fat Loss Tips! Shocking!

3) People suffer from "The dieter's Paradox", where they erroneously believe that adding something supposedly healthy to Crap-In-A-Bag/Box/Bottle (CIAB) reduces the total number of calories. See The Dieter’s Paradox – Research Review.

Why weighing yourself regularly can be a waste of time.

As mentioned previously, scales cannot distinguish between muscle, body-fat, glycogen+water, urine, faeces etc. Bodyweight can fluctuate considerably on a day-to-day basis. The following list (source forgotten!) lists the effect of various things on body-weight.

Thing________________________Weight change (lb)
Glycogen supercompensation________~+10
Glycogen replenishment/depletion_+/-4 to 5
Pre-menstrual water retention_____~+5
Eating a high-sodium meal__________+2 to 3
Fluid retention on airplane flight +2 to 3
Going to the loo (No.2)____________-1 to 2
Going to the loo (No.1)___________~-0.5
Drinking a mug of tea_____________~+0.5

So step away from the scales. There's nothing to see here, folks! If your belt/clothes are getting tighter, reduce the frequency of eating "treats" (moreish foods that are usually high in sugar, fat, salt & flavourings).

And finally, a little light relief. If I just waffle on about Diet & Nutrition all the time, it can get boring. So here's a YouTube video of a really cool cat that must have watched the Doctor Who episode "Blink". You know, the one with the Weeping Angels. Ninja cat comes closer while not moving!

Everyone is Different.

Updated text in bold green.
If there is one thing that I have learned over the years of research into Diet and Nutrition, it's this: Everyone is Different. When I first discovered Low-carb Diets (thanks to the late Dr Atkins), I thought that it was the One True Diet, and I became a bit of an "Atkins Diet" bore telling everyone how wonderful it was and suggesting that everyone should be on it.

I now know that what suits me doesn't necessarily suit someone else. So why do "Healthy Eating" guidelines assume that everyone is the same and tell everyone to get 15% of their total calories from proteins, 55% from carbohydrates and 30% from fats?

To illustrate just how different people are, here's Fig. 2 from Determinants of the variability in respiratory exchange ratio at rest and during exercise in trained athletes. Used with permission.

Respiratory Exchange Ratio (RER) (a.k.a. Respiratory Quotient (RQ)) is the ratio of carbon dioxide breathed out to oxygen breathed in. This ratio depends on the fuel that the body is burning for energy. For example, if the body is burning 100% fat, RER = 0.7. If the body is burning 100% carbohydrate aerobically, RER=1.0. If the body is burning 100% carbohydrate anaerobically (flat-out sprinting), RER > 1.0. RER goes up and down depending on intensity of exercise, food intake (eating protein and/or carbohydrate increases it and extended fasting reduces it). Increasing cardiovascular fitness reduces RER.

The top diagram is a histogram of fasted RER and % fat oxidation vs. number of subjects. At the left-hand end of the histogram, there are two cyclists with a fat oxidation of 93 - 100%. At the right-hand end of the histogram, there is one cyclist with a fat oxidation of 20 - 27%.

There's a helluva big difference between burning 93 - 100% fat at rest and burning 20 - 27% fat at rest. Interestingly, average fat oxidation is 66%, which means that average carb oxidation is 34%. So, on average, at rest, people burn twice as much energy from fat as from carbs. So why do current "Healthy Eating" guidelines recommend almost twice as much energy from carbs as from fats for everyone, including sedentary people?

As exercise intensity increases, the peak in the histogram shifts to the right as shown in the lower diagram. At 25% full work-load, mean fat oxidation is ~53%. At 50% full work-load, mean fat oxidation is ~37% and at 75% full work-load, mean fat oxidation is ~13%.

I suspect that at 100% full work-load, mean fat oxidation is 0% i.e. 100% of energy is obtained from carbs when sprinting flat-out. Somebody on a very low carb diet like Atkins induction (~20g net carbs/day) could keel over with hypoglycaemia if they exercise for any length of time at this rate.

As there is so much variation from person to person, you must find out for yourself your own optimum proportions of proteins, fats and carbohydrates and these depend upon the intensity and volume of exercise you do. It all sounds a bit complicated but it isn't really.

Just apply the principle of "Eat, monitor and adjust accordingly" as Toxic Toffee (ex-Muscletalk member) always used to say. The eating bit I will advise on in future Blog posts. The monitoring bit does not involve the use of bathroom scales.

Hang on, isn't "dieting" all about losing excess weight? Not necessarily. Remember the old joke: Q. What's the best way to lose 5lbs of ugly flab? A. Cut your head off! As your body is made up of water, muscle, fat, bones, cartilage, tendons, organs, glycogen, skin etc and your scales can't tell the difference between them, losing weight the wrong way can make you less healthy. However, losing weight the right way will make you more healthy.

If you starve yourself or skip breakfast or go for a fast run before eating breakfast, as your body is lacking in glycogen and amino acids, a large amount of a corticosteroid hormone called cortisol is secreted which converts muscle into amino acids, then glucose. It also suppresses your immune system and weakens your skin and bones.

Unless you have a lot of muscle to spare, it's body-fat that you should be losing, and to monitor this, either use a tape-measure around your waist, or check how loose/tight your clothes are, or strip-off and jump up and down in front of a full-length mirror. As Big Les (Muscletalk Moderator) says, "If it jiggles, it's fat!".

So, what happens if you eat too many carbs but your body doesn't burn them fast enough? Initially, carbohydrate intake tops-up liver and muscle glycogen stores, which increases carb-burning to compensate. The liver can store about 70g of glycogen and muscles can store about 400g of glycogen. If, despite increased carb-burning, more carbohydrate is consumed than is burned, glycogen stores continue to fill. When glycogen stores become full, RER increases to 1.0 and 100% of energy is derived from carbohydrate. Getting 100% of energy from carbohydrate means that zero fat is burned, so filling glycogen stores by eating loads of carbohydrate is not a good idea if you want to burn body-fat. Once glycogen stores are full, any additional intake of carbohydrate beyond that which is burned passes through the lipogenesis pathway - this basically means that carbs are turned into fat - which you end up wearing as body-fat. But there's even worse news. On the way to being worn as body-fat, fat is in the blood as triglycerides. This is bad for the cholesterol particles in your blood. See the Blog on Cholesterol and Coronary Heart Disease. What happens if you eat too few carbs? As stated above, a "carb-burner" taking in insufficient carbs could get hypoglycaemia.

How many grams of carbohydrate per day does it take to promote lipogenesis? Someone at rest burns ~1kcal/minute. If this is derived 100% from carbohydrate, this is equivalent to 0.25g of carbohydrate /minute, or 15g of carbohydrate /hour, or 360g of carbohydrate /day. Therefore, sedentary people who consistently eat more than 360g of carbohydrate /day will produce significant triglycerides. People who have The Metabolic Syndrome/Syndrome-X (a high proportion of people who have excess belly fat) have increased lipogenesis and higher serum triglycerides than healthy people.

Just discussing weight again for a moment, it's often said that all diets are the same, as weight loss is all about calories. This is true. See Is a Calorie a Calorie? However, body composition is determined by a combination of macro-nutrient proportions (i.e. the relative amounts of protein, carbohydrates and fat that you eat) and the intensity and volume of exercise.

So, if all you're interested in is weight loss, just count calories. If however, you wish to lose body-fat without losing muscle, you need to know how to determine what proportions of proteins, carbs and fats to eat (it's not that critical, but many people get it totally wrong). You need to know the difference between good carbs and bad carbs and good fats and bad fats. You need to know the best times to eat proteins, carbs and fats (it's not that critical, but many people get it totally wrong). You need to know the difference between good exercise and bad exercise.

Cont'd on We are not all the same.