Body fat: 25.8%
Sleep: 7hrs 20min (4hrs31+2hrs49)
BP: 127/69 @64bpm
Day#5 and I’ve put on some weight.
How did that happen?
Well, last night I had some beef broth. According to Dr Fung, beef broth is permissible on an extended fast – not that 5 days is necessarily yet an extended fast. But I batched up some broth following the recipe in his book – The Complete Guide to Fasting.
About 1kg of beef bones – I used neck bones, without any real meat on them, mainly bones and marrow. Then some celery, some carrots, an onion, and some leeks. And Himalayan salt. I boiled it down and had two cups – about 250ml each. It was broth only, no solids at all.
I had the broth not because I felt hungry, but because I am writing an original screenplay at the moment and I need absolute acuity of thought, and I found yesterday I was a bit fuzzy-minded. I was hoping the nutrients in the broth might fix that. I wasn’t expecting to put on weight!
Anyway, what’s interesting is that whilst I put on 0.4kgs of weight (when really I should have lost about 1kg of weight,) my body fat percentage has come down quite a bit – from 27.7% when I started to 25.8% today.
No broth today – only tea.
Saturday here so I mowed the lawn, which constituted my exercise for the day. Took me 1hr20mins. Felt good and strong. Listening to Eric Clapton might have helped.
I’m no longer feeling any hunger at all – I miss food now for the ritual of meals, and the companionship that comes with it.
So here’s another myth that Dr Fung busts regarding fasting: fasting makes you burn protein…
One persistent myth of fasting is that it burns muscle, that our body, if we’re not eating, will immediately start using our muscles as an energy source. This does not actually happen. The human body evolved to survive periods of fasting. We store food energy as body fat and use this as fuel when food is not available.
Muscle, on the other hand, is preserved until body fat becomes so low that the body has no choice but to turn to muscle. This will only happen when body fat is at less than 4 percent. (For comparison, elite male marathon runners carry approximately 8 percent body fat and female marathoners slightly more.)
If we did not preserve muscle and burn fat instead when no food is available, we would not have survived very long as a species. Almost all mammals have this same ability. Real-world studies of fasting show that the concern over muscle loss is largely misplaced. Alternate-day fasting over seventy days decreased body weight by 6 percent, but fat mass decreased by 11.4 percent and lean mass (muscle and bone) did not change at all.
During fasting, the body switches from burning sugar (carbohydrates) to fat for energy. Protein is spared. At baseline, eating normally, energy comes from a mix of carbohydrates, fat, and protein. As you start fasting, the body increases carbohydrate oxidation. This is just a fancy way of saying that it is burning sugar, in the form of glycogen, for the first twenty-four to forty-eight hours after you stop eating, until it runs out of glycogen.
With no more sugar to burn, the body switches to burning fat. Fat oxidation increases as carbohydrate oxidation decreases toward zero. At the same time, protein oxidation—that is, burning protein, such as muscle, for fuel—actually decreases. The normal protein breakdown of around seventy-five grams per day falls to fifteen to twenty grams per day during fasting. Rather than burning muscle during fasting, we start conserving muscle. Much of the amino acids that are broken down during regular turnover of cells are reabsorbed into new proteins.