Your excess fat eats (some of) your excess food

I have this recurring nightmare. I indulge myself with that delicious but superfluous baguette for lunch -- tomato and thick slices of brie, with perhaps a caramel bar to follow - and slowly and surely I'm going to blow up.

All those years of 5:2 fasting and self-denial put to waste.

But it won't happen - at least, not to infinite weight. The extra fat is real but surely it's self-limiting: after all, it metabolises. That extra fat needs extra calories. A new equilibrium will be born.

The health-police don't want you to know this, but a quick back of the envelope calculation makes it clear.

They say men should consume 2,500 calories per day and women 2,000. Notice that the larger bodies of men already require more calories to maintain themselves. Apparently, the average UK man weighs 84 kg while the average UK woman weighs 70 kg.

And so we get get this rough-and-ready graph.

We're ignoring the differences between bone, muscle and fat plus the fact that women have a third more fat in their bodies than men. If we had it right, the constant would be zero.

But, just roughly, if you eat an extra 360 calories a day (my superfluous lunch) then your equilibrium weight will be pushed up by .. 10 kg.

Oops! A price not worth paying!

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In fact my weight has gone up from its target 67 kg to almost 69 kg since Christmas.

Could I be consuming (36 *2 =) 70 calories a day too much? No, nothing so benign.

Building this extra weight (gaining 1 kg of fat = 7,700 calories) is far more expensive than simply maintaining it (maintaining 1 kg of fat = 36 calories/day).

I think I see what that baguette has been doing .. and why expansion might not stop anytime soon .. .

Scotoma after exercise

So this evening was the second time in two months that I've experienced a scotoma.

"5th November 2016. After weights exercise, a visual illusion to the right of central visual field (both eyes separately). A flickering jagged arc. This is consistent with a scotoma. Same phenomenon with either eye closed. After half an hour it began to move out and enlarge while retreating further into peripheral vision. After an hour it disappeared.

This phenomenon reappeared 19th January 2017, a couple of hours after fairly intense exercise, at 6.10 pm. Visible duration 20 minutes. Started at the centre of the visual field, a flashing-lightning V-shape with vertex at 8 o'clock. Gradually got larger until it vanished past the boundary of the visual field.

Other relevant information: I skipped lunch today as part of my weight-control programme."

After the first time I checked with Wikipedia to discover scintillating scotoma - it looks like this:

although as mentioned I'm seeing a well-defined white jagged shape, growing slowly in size.

I'm not the only one. A google search for "Scotoma after exercise" returns this.

"f you read the title and opened this post, you most likely do suffer from Scintillating Scotoma. You know, start to lose part of vision because of a flashing spot .. . The flashing zig-zag moves to outer edge of eyes, then, after 20 minute or so, goes away.

The common consensus is that is a migraine headache, without the pain.

Anyhow, since I started upping my intensity on the bike trainer workouts, I seem to be getting them after each workout. Could it be clustering since the intensity is greater? I used to get them sometimes after early season races, then as the season wore on and I got used to the intensity, they went away.

I know they're not really an issue, but, hard not go to into a mini-panic each time. "

Wikipedia talks about "cortical spreading depression" as the cause:

"a wave of electrophysiological hyperactivity followed by a wave of inhibition. Spreading depolarization (SD) describes a phenomenon characterized by the appearance of depolarization waves of the neurons and neuroglia that propagates across the gray matter at a velocity of 2–5 mm/min.

SD can be induced by hypoxic conditions and facilitates neuronal death in energy-compromised tissue. SD has also been implicated in migraine aura, where SD is assumed to ascend in well-nourished tissue and is typically benign in most of the cases, although it may increase the probability in migraine patients to develop a stroke."

I don't suffer from migraine, and the effect is purely visual although if pressed, I might admit to an ill-defined feeling of 'headiness' which persists for rather longer.

It seems benign and not a precursor to anything serious so I'm inclined to see it as no more than a warning to ease up a little on high-intensity training, which is currently sending my pulse north of 156, close to the maximum heart rate (207 - 0.7 * 66 = 161) for my age.

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Apart from any intrinsic interest, I put this post up to compensate for the lack of engagement many of you feel for my science posts - such as the one posted earlier - fascinating though they are 😐 ..

Roy asks in the comments how I know this. Family verbal feedback and - to an extent - view counts.

Diary: exercise bike + many-worlds (MWI) + Game of Thrones + Lee Child

Breakfast: a bowl of mixed nuts, sliced banana, a small satsuma, dunked with tablespoons of natural yoghurt. No cereal today due to a 1kg weight excess (71 kg this morning).

This morning: my replacement exercise bike arrived from Germany. Spent an hour putting it together - you seldom get a second chance to assemble an exercise bike but it does go faster. Shredded the large cardboard box for recycling while bagging up the polystyrene blocks.

The bike works.

Lunch: a tin of mulligatawny soup followed by Clare's home-made pizza topping on naan bread (very nice!). I finish up with an apple and a square of that 90% cocoa chocolate which, perhaps because of its bitterness, is rather attractive.

Afternoon: I hoover polystyrene & cardboard litter from this morning's assembly.

I try to continue my reading of "The Emergent Multiverse" - I had not fallen off a cliff on chapter 3, where David Wallace does the math, but I can't concentrate on the later probability discussion today.

I read 'West Hunter' instead, and discover a promising SF book I haven't read. I order: "Rainbow's End" by Vernor Vinge.

I also dip into the current-final volume of ASOIAF: "A Dance With Dragons: Part 2 After The Feast".

Dinner is predicted to be Minced Beef En Croûte and peas. We are still avoiding 'greens' and at Waitrose tomorrow we'll be shopping for substitutes. Our list so far: squash, sweet potato, vegetable samosas, mushroom ravioli, baked beans (small, low sugar) and anything similar which comes to mind as we scan the shelves.

No trips out today, except down the drive to put the recycling out. Like yesterday, it's been raining all day and the clouds loom thick and dark.

This evening I'll continue reading to Clare. It's Lee Child's "Killing Floor" (originally recommended by my brother) and we're still in the county jail, mixing it with the gangs. Gritty.

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No-one thinks that EM drive works.

A shame.

You're similar to your spouse in so many ways ...

You already knew that spouses were correlated for intelligence.

R Plomin and I J Deary have this to say:

" ... Assortative mating is greater for intelligence (spouse correlations ~0.40) than for other behavioural traits such as personality and psychopathology (~0.10) or physical traits such as height and weight (~0.20)."

Here's what a correlation of 0.4 looks like (top right).

Marginal Revolution gets excited about this result though:

"Nordsletten and colleagues find an amazing amount of assortative mating within psychiatric disorders.

"Spouse tetrachoric correlations are greater than 0.40 for attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and schizophrenia.

"The next highest spouse correlation emerged for substance abuse (range, 0.36-0.39).

"Assortative mating was significant but far less substantial for other disorders, such as affective disorders (range, 0.14-0.19)."

They conclude:

"Beyond genetics and genomics, assortative mating matters because it means that the person closest to an individual with a psychiatric disorder is also likely to have psychiatric problems, which could exacerbate problems for both spouses and their offspring."

The ubiquity of assortative mating - who knew?

The Dieting Mirage

Every day you eat three to five pounds of food - where does it go? Most of it is (or is metabolised to) water which leaves the body as sweat, moist breath or liquid waste. Between half a pound and a pound is excreted as solid waste (eat more fibre!). The remainder is exhaled as yet another metabolic by-product - carbon dioxide. Oh, and maybe some of it adds to your unsightly girdle of fat!

Remember conservation of mass?

Suppose you go on a diet; you reduce your day's food intake by 1,000 Calories (i.e. half rations). Next day you weigh yourself. Triumph! ... you weigh a pound or two less!

So now it's an eating day again. Next day, omigod ... you've gained two pounds!

This is not a story of yo-yo dieting. You're weighing differences in internally-carried food!*

A pound of fat provides around 3,000 Calories. If you reduce your daily intake by 1,000 Calories you will metabolise of the order of one third of a pound of fat to compensate. Honestly, you will not notice this on the scales. If you can maintain a 1,000 Calorie daily deficit for a whole week (a big ask!) you might lose that magic two pounds for real - something noticeable behind the daily ups and downs of eat-process-excrete! Think incremental, marginal gains and stick at it.
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* I don't think we should forget the gut microbiome either. Weighing in at two to three pounds, it seems plausible that this mass of symbiotic bacteria should be quite responsive to levels of nutrition, dying back when the host is dieting and re-expanding once the good times return. This additional (non-fat related) ebb and flow of weight probably occurs on a timescale of some days: yet another delayed reaction to dietary change.

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And now for something completely relaxing: take your shoes off, lean back and just chill with this ...

Thanks to Marginal Revolution.

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In other stuff, we have not seen the painter for some days after an initial half day of preliminary wall-scraping, an absence due entirely to rain and inclement winds. We hope to see him again tomorrow.

Free Energy is a thermodynamics concept: it's the amount of energy in a system which can do useful work. It's the reason why only differences in temperature can power machines like steam engines: a uniformly warm heat-bath can't make anything work. This has (negative) implications for life in the outer solar system. Remember Europa in the book/film 2001?

How do we know it's Spring? A vole's head, tail and unidentifiable lump on the kitchen floor yesterday morning + the animal has taken to ambush-hunting birds in the bushes under the feeders. Just thought I'd share ...