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Kindle Notes & Highlights
by
Jason Fung
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January 22 - January 26, 2019
Most definitions of fasting allow noncaloric drinks only.
It’s important to note that this fast generally includes zero salt. Without salt, the body cannot hold onto water, and therefore there is some risk of dehydration.
This means that as long as the water-only fast is limited in duration, your salt requirements will be fairly low, and salt deficiency shouldn’t be a problem.
To make coffee “bulletproof,” you add fat in the form of coconut oil, medium-chain triglycerides (MCT oil), or butter from grass-fed cows.
The “fasting-mimicking diet” is a diet created by researchers to re-create the benefits of fasting without actual fasting.
To me, it is far simpler to follow five days of regular fasting per month.
The key to therapy is prolonged therapeutic ketosis (blood ketones in the range of 3–6mM), together with reduced blood glucose levels (3–4 mM).
GKI ratios of 1.0 or below would best represent the therapeutic range.
The IDM fast permits water, tea, and coffee. Sugar, honey, agave nectar, and other sweeteners are not permitted.
The IDM fast also allows homemade bone broth, which both makes fasting easier and may help prevent salt deficiency during longer fasts.
As a matter of routine, I eat LCHF and intermittent fast for a minimum of 18 hours, and I do a water-only fast for 2 to 3 days a week.
Aim to drink two liters of water and other fluids daily. As a good practice, start every day with eight ounces of cool water to ensure adequate hydration.
Diluted apple-cider vinegar in water may help lower your blood sugar.
All types of tea are excellent choices, including green, black, oolong, and herbal. Green tea is an especially good choice during a fast: the catechins in green tea are believed to help suppress appetite.
Herbal teas are not true teas because they do not contain tea leaves. However, they also are great for fasting.
Coffee has many health benefits that are just being recognized—for instance, it may reduce the risk of type 2 diabetes and is a great source of antioxidants.
We often advise people to add a good pinch of sea salt to their homemade bone broth.
Sea salt also contains other trace minerals, such as potassium and magnesium, which may be particularly beneficial during fasting.
There is also a small amount of protein and some minerals (calcium and magnesium) in bone broth, so technically, any fast that allows broth is not a true fast.
Traditional hunter-gatherer societies virtually never develop obesity or diabetes, even during times of plentiful food.
So, despite all the modern teeth gnashing about red meat and saturated fats, it seems that our ancestors had little problems eating them.
What matters most is our insulin response to food, since obesity is largely a problem of excessive insulin.
the timing and frequency of meals is as important as the composition of the meal.
The term intermittent fasting simply means that periods of fasting occur regularly between periods of normal eating.
Shorter fasts are generally done more frequently, even daily, while longer fasts—twenty-four to thirty-six hours is the most common duration—are usually done two to three times per week.
I categorize fasting periods as short (less than twenty-four hours) or long (more than twenty-four hours), but this is somewhat arbitrary.
Two major dietary changes happened starting in 1977.
Daily twelve-hour fasting introduces a period of very low insulin levels during the day.
The daily sixteen-hour fast certainly has more power than the daily twelve-hour fast, but it should be combined with a low-carbohydrate diet for the best effect.
20-Hour Fasts: “The Warrior Diet”
Hofmekler’s diet also emphasizes natural, unprocessed foods and high-intensity interval training,
Almost all our hormones, including growth hormone, cortisol, and parathyroid hormone, are secreted in a circadian rhythm.
Circadian rhythms have evolved to respond to differences predominantly in ambient light, as determined by the season and time of day.
Weight gain is driven by insulin, and the higher insulin response in the evening was translating into more weight gain for the dinner group.
Eating the largest meal in the evening seems to cause a much larger rise in insulin than eating earlier.
But personal experience and studies show that hunger is lowest in the morning, and breakfast is typically the smallest, not the largest, meal of the day.
Ghrelin, the hunger hormone, rises and falls in a natural circadian rhythm, with a low at 8:00 a.m. and a high at 8:00 p.m.
Interestingly, during extended fasting, ghrelin peaks during the first two days and then steadily falls.
Hunger is maximally stimulated at approximately 7:50 p.m. At this time, insulin is maximally stimulated by food, which means that the same amount of food results in higher insulin levels.
So the optimal strategy seems to be eating the largest meal in the midday, sometime between noon and 3:00 p.m., and only a small amount in the evening hours.
In Part I, we talked about how insulin and insulin resistance are at the heart of both obesity and type 2 diabetes.
Since all foods increase insulin to some degree, the most efficient method of lowering insulin is eating nothing at all.
But because breaking insulin resistance requires not just low insulin levels but persistently low levels, we need longer fasting periods.
I cannot stress enough that if you do not feel well at any point, you must stop fasting. You can be hungry, but you should not feel sick.
A twenty-four-hour fast involves fasting from dinner to dinner, or breakfast to breakfast, whatever you prefer.
This fasting regimen is also the most easily incorporated into everyday life.
Nutrient deficiency is not a major concern with a twenty-four-hour fast.
You could follow this regimen daily, although most will get good results doing a twenty-four-hour fast two to three times per week.
The fasting period ensures that you burn through quite a bit of your stored energy, and deliberately trying to cut calories further is often difficult in the long term.
The 5:2 diet consists of five normal eating days. On the other two “fast” days, women may eat up to 500 calories per day and men up to 600 calories.
