Intermittent Fasting
Greens drinks (e.g. Athletic Greens)
Drinking one will technically break your fast. They're about 55 calories
Some people say they can do it without impacting fasting results (but I'm unsure how to evaluate that)
Recommended to drink these drinks "first thing in the morning for optimal absorption"
The alternative to this if not wanting to break fast is to drink slightly before lunch, i.e. 15 minutes
Research stage
Research is still in its early stages. Many of the studies were small, short-term or conducted in animals. Many questions have yet to be answered in higher quality human studies (source)
Clinical research studies of fasting with robust designs and high levels of clinical evidence are sparse in the literature. (source)
Effects on muscle
Some studies have shown that small amounts of lean mass (1 kg or 2 pounds) may be lost after several months of intermittent fasting (1Trusted Source). However, other studies have shown no loss of lean mass (source)
Intermittent fasting requires you to eat fewer calories and eat less frequently than a normal diet. Because of this, you may have trouble getting enough calories and protein to build muscle. Overall, this may not be the best diet for muscle gain. (source)
Intermittent fasting requires you to eat fewer calories and eat less frequently than a normal diet. Because of this, you may have trouble getting enough calories and protein to build muscle. Overall, this may not be the best diet for muscle gain. (source)
In that 8 hour window, just eat plenty of protein and stay away from sugar. (source)
Will Fasting Cause Muscle Loss? All weight loss methods can cause muscle loss, which is why it’s important to lift weights and keep your protein intake high. One study showed that intermittent fasting causes less muscle loss than regular calorie restriction (16Trusted Source). (source)
Effect on weight
Fasting is definitely okay if you aren’t trying to lose weight. You just eat at maintenance calories (source)
If you’re underweight or have a history of eating disorders, you should not fast without consulting with a health professional first. (source)
Short-term fasting may increase your metabolic rate by 3.6–14% (source)
Isn't breakfast important?
Isn’t It Unhealthy to Skip Breakfast? No. The problem is that most stereotypical breakfast skippers have unhealthy lifestyles. If you make sure to eat healthy food for the rest of the day then the practice is perfectly healthy. (source)
There is no evidence to back up that breakfast is the most important meal of the day, nutritionally all of your meals are as important. That saying is just good marketing to sell more cereal. (source)
As other commentators have stated, many of the studies which try to prove that breakfast is good for us are flawed for two reasons: Firstly, they are nearly always funded by Kelloggs or similar, and secondly, they are based on correlation and not causation. (source)
Advice when doing it
When you eat, let yourself eat till you are satisfied. (source)
You may also feel weak and your brain may not perform as well as you’re used to. This may only be temporary, as it can take some time for your body to adapt to the new meal schedule. (source)
I do mine opposite of most. I prefer to eat my calories first thing in the morning and let them digest and burn off throughout the day. I skip lunch and dinner. Works better for me and I sleep alot better I've found out as well. (source)
Limbic vs Somatic vs Appetite-driven hunger
Somatic hunger refers to the feeling that you have in your belly when you are hungry and you have some cramping sensation and you kind of notice that you’re hungry. That sensation is often just driven by your schedule. It happens at the same time every day, and kind of reminds you to eat. (source)
Appetite-driven: When you eat and you’re not feeling any pain or cramps or any sensation in your belly, but you still feel compelled to eat, and you don’t really know why you’re eating—you’d rather not eat, but you keep eating, that’s appetite-driven hunger. (source)
Limbic hunger, which means that when you start to eat something, it kind of opens the door for lots more eating, and you eat until you’re full, no matter what. (source)
Limbic hunger was very, very powerful survival tool, but in a world that has an abundance of food available, it becomes something that is not necessarily to our advantage. (source)
What about occasionally breaking
Breaking on weekends curbs some of the benefits. This has to do with the fact that the benefits of a schedule of feeding come a lot from the "body clock" topic (source)
Effects on sleep
Along with a decrease in sleep arousals a 1-week fasting period promotes the quality of sleep and daytime performance in non-obese subjects. The observed decrease in PLM might point to a nutritional modification of brain dopaminergic functions. In terms of evolutionary development, an improved daytime performance during periods of food deprivation could have been beneficial for the success in search for food. (source)
In one study of healthy adults, participants found that their sleep quality improved on several levels after a week of intermittent fasting. (source)
A human that is fasting will sleep less, as the brain is tricked into thinking that food has suddenly become scarce (source: Why We Sleep book)
Notes
The 16/8 method: Also called the Leangains protocol, it involves skipping breakfast and restricting your daily eating period to 8 hours, such as 1–9 p.m. Then you fast for 16 hours in between. (source)
Many people find the 16/8 method to be the simplest, most sustainable and easiest to stick to. It’s also the most popular. (source)
Fasting has been a practice throughout human evolution. Ancient hunter-gatherers didn’t have supermarkets, refrigerators or food available year-round. Sometimes they couldn’t find anything to eat. As a result, humans evolved to be able to function without food for extended periods of time. (source)
Your body adjusts hormone levels to make stored body fat more accessible. (source)
Human Growth Hormone (HGH): The levels of growth hormone skyrocket, increasing as much as 5-fold. This has benefits for fat loss and muscle gain, to name a few (source)
Insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels make stored body fat more accessible (source)
Cellular repair: When fasted, your cells initiate cellular repair processes. This includes autophagy, where cells digest and remove old and dysfunctional proteins that build up inside cells (source)
Gene expression: There are changes in the function of genes related to longevity and protection against disease (source)
Evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span. (source)
Weight loss is the most common reason for people to try intermittent fasting (source)
Inflammation: Some studies show reductions in markers of inflammation, a key driver of many chronic diseases (source)
Heart health: Intermittent fasting may reduce “bad” LDL cholesterol, blood triglycerides, inflammatory markers, blood sugar and insulin resistance — all risk factors for heart disease (source)
Cancer: Animal studies suggest that intermittent fasting may prevent cancer (source)
Brain health: Intermittent fasting increases the brain hormone BDNF and may aid the growth of new nerve cells. It may also protect against Alzheimer’s disease (source)
Anti-aging: Intermittent fasting can extend lifespan in rats. Studies showed that fasted rats lived 36–83% longer (source)
Intermittent fasting can make things easier, as you don’t need to plan, cook or clean up after as many meals as before. (source)
There is some evidence that intermittent fasting may not be as beneficial for women as it is for men. (source)
There are a number of anecdotal reports of women whose menstrual period stopped when they started doing IF and went back to normal when they resumed their previous eating pattern. (source)
Water, coffee, tea and other non-caloric beverages are fine. Do not add sugar to your coffee. Small amounts of milk or cream may be okay. (source)
Fasted workouts are fine. Some people recommend taking branched-chain amino acids (BCAAs) before a fasted workout. (source)
We workout and focus even better when fasted (source: Huberman)
Much of what has been studied in humans for time restricted feeding (TRF) or intermittent fasting (IF) began in the late 1970s and culminated around the early 1990s. It wasn't until recently in the late 2010s when a second academic renaissance began studying the effects of IF in both animal models of disease and physiology, but also clinical research involving human subjects. (source)
Anecdotal Benefits of IF (source)
Binge / appetite correction
You want to eat healthier
More energy
Better focus
Better appreciation for those who are truly starving
Awareness of the pressures of society to make us eat
Less time spent worrying about food and cooking
Attempt to cool down internal body temp throughout the day
More time in the day for other activities besides cooking/eating
What to do about super occasional late drinking/eating socially? : intermittentfasting
Lots of suggestions to be totally ok with occassional breaks, and some even saying to lean into them
Focus on healthy, high-fiber, vegetable-rich foods during the feeding periods and moderate other less-healthy options. (source)
The general rule of thumb is that if you stay under 50 calories, then you'll remain in the fasted state. (source)
Though I think Huberman has emphasized the type of calories is super important here as well. It's all about blood glucose and insulin levels
Links
Link containing answers on if some things break a fast or not (i.e. Athletic Greens, spinach, sugar free gum, Crystal Light)
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