Weight Loss & Fasting with Dr. Jason Fung MD
Dr. Jason Fung, MD, a prominent nephrologist and an expert in diabetes, obesity, and fasting, explains intermittent fasting. In this enlightening video, he expounds upon different types of fasts and mentions the health benefits that they provide. Dr. Fung also discusses measures to take to ensure that you fast safely.
We saw last week with the Biggest Loser study that basal metabolism plummets when you lose weight with calorie reduction. As contestants lose weight, they burn a lot less energy – up to 800 calories per day less than before. Some of that is expected, since there is less body tissue to maintain, but nevertheless, these contestants burn far less than . . .
Contrary to what most people believe, long term weight loss is not simply about cutting a few calories here and there. Sure, it sounds like it works, but the bottom line is that it does not. This has been proven in countless studies and also the countless tears of unsuccessful dieters desperately counting their calories like Ebenezer Scrooge counting his pennies.
Fasting is a time tested and ancient tradition. It has been used not only for weight loss, but to improve concentration, extend life, prevent Alzheimers, prevent insulin resistance and even reverse the entire aging process. There is much to talk about here so we begin a new subsection “Fasting”.
There is nothing new, except what has been forgotten – Marie Antoinette
So the forgotten question of weight loss is . . .
There are many misconceptions about fasting. It is useful to review the physiology of what happens to our body when we eat nothing.
Glucose and fat are the body’s main sources of energy. If glucose is not available, then the body will adjust by using fat, without any detrimental health effects. This is simply a natural part of life. Periods of low food availability have always been a part of human history.
In our previous post (part 2), we took a quick overview of the physiology of fasting. I’d like to take a more in-depth look at some of the studies that have been done to really try to understand what is actually happening when we fast. Today I want to focus in on human growth hormone (HGH).
Insulin is the main driver of both obesity and type 2 diabetes. The key to reversing both conditions is therefore not “How do we reduce calories?”, but instead “How do we reduce Insulin?” There are almost no drugs that will do this. There are actually two classes of medications that consistently reduces insulin – one by a lot, one by a little.
Many myths are associated with fasting. These myths have been repeated so often that they are often perceived as infallible truths. Some of the these myths include:
Fasting puts you in starvation mode
Fasting will overwhelm you with hunger
Fasting causes overreacting when you resume feeding
Fasting will make you lose muscle
Fasting deprives the body of nutrients
Fasting causes hypoglycemia . . .
There are many different fasting regimens. Let’s be very clear to start, though. There is simply no ‘best’ one. They all work to different degrees for different people. Just as some people prefer steak to chicken, there is no right or wrong answer. One regimen will work for one person but be utterly ineffective in the next.
There are several longer duration fasting regimens that are available. I arbitrarily divide it at 24 hours but there is no physiologic reason to do so, other than for classification purposes. There is no magic dividing line. We covered fasting regimens using periods less than 24 hours in our last post. This post will cover those schedules that use fasts longer than 24 hours.
There really is no upper limit to fasting regimens. Once again, I will add a cautionary note. If you are taking medications or especially if you have diabetes, you need to discuss this with your physician before starting. The blood sugars often come down with fasting regimens, but if you are taking medications, it may come down too low. This is a potentially fatal . . .
Some would argue that the beneficial effect of fasting is due to the caloric reduction. But why is there such a striking difference between reducing calories and fasting? Caloric Reduction as Primary (CRaP) has been tried innumerable times, and failed virtually every single time. Yet fasting is often effective where simple caloric reduction is not. The short answer is . . .
Not surprisingly, the use of fasting for weight loss has a long history, since it’s, kind of, like, obvious. I mean, everybody understands that if you do not eat, you are highly likely to lose weight. Duh. Which makes it even more surprising how much people fear missing even a single meal, let alone fast for a prolonged period of time. They think that fasting (not eating) will make you fat.
Feasts are an important part of life. This is a vitally important fact to acknowledge. That is, every single important celebration is marked by feasting. Eating is a celebration of life. Any diet that does not acknowledge this fact is doomed to failure. We eat cake on our birthday. We eat holiday feasts like Thanksgiving. We celebrate Christmas dinner.
We’ve dealt extensively with the science of fasting, but sometimes there are many practical considerations that need exploring, too. Fasting, like anything else in life requires some practice. In days past, when religious fasting was a communal practice, these sort of practical tips were passed on from generation to generation. If not, friends would often have useful advice . . .
Will fasting make me tired? In our experience at the Intensive Dietary Management Clinic, the opposite is true. Many people find that they have more energy during a fast—probably due to increased adrenalin. Basal metabolism does not fall during fasting but rises instead. You’ll find you can perform all the normal activities of daily living. Persistent fatigue is not a normal . . .
What is the advantage of using a strategy based on intermittent fasting versus simple dietary changes alone – such as the LowCarb HighFat diets that we prefer? There are several good ones.
Reason #1 Simplicity
When I started out my clinic, I tried to persuade people to adopt the LCHF diet. I was doing this for people of all ages, of all nationalities.
It seems that there are always concerns about loss of muscle mass during fasting. I never get away from this question. . . . [S]omebody always asks, “Doesn’t fasting burn your muscle?”
Let me say straight up, NO.
. . . If you are concerned about losing weight and reversing T2D, then worry about insulin. Fasting and LCHF will help you. If you are worried about muscle mass, then exercise . . .
Does fasting increase your hunger to unimaginable and uncontrollable dimensions? This is often how fasting is portrayed, but is it really true? From a purely practical standpoint, it is not. From my personal experience with hundreds of patients, one of the most consistent, yet surprising things reported is the reduction, not an augmentation of hunger.
The relationship between fasting and hunger is, without doubt, the #1 concern we hear. Overcoming hunger seems a daunting task, stemming from a misunderstanding of actual hunger. This is mildly ironic, since my guess is that 95% of us have never, truly been hungry in the sense of starvation, where we did not know when we would be able to eat again.
It is sometimes useful to consider things from an evolutionary standpoint. We can look back at early humans and make some general recommendations. Granted, there is little or no proof, but the exercise is still useful and interesting.
There is often great debate about whether we should be eating constantly, or occasionally.
Complications with refeeding were first described in severely malnourished Americans in Japanese prisoners of war camps in World War 2. It has also been described upon treatment of long standing anorexia nervosa, and alcoholic patients. It is important to have an understanding of these syndromes if you are attempting an extended fast – usually greater than 5-10 days at a time.
One of the major mistakes made by the Calories In/ Calories Out (CICO) hypothesis is . . . that all foods can be reduced to their caloric equivalent and then stored in a single compartment in the body (Calories In). The body then uses this energy for basal metabolism and exercise (Calories Out).
. . . [T]his model is a complete fabrication.
The Biggest Loser is a long running American TV reality show that pits obese contestants against one another in a bid to lose the most weight. The show regularly comes under fire from physicians and other health professionals for its over the top portrayal and its fat shaming tactics.
Is it possible to exercise while fasting? This is a common question we hear all the time. People think that food gives them energy and therefore it will be difficult to fast and exercise at the same time. Some people with physically demanding jobs feel that they could not fast and work properly. What’s the truth?
How does fasting affect brain function? There is very little reliable human data, but some very interesting animal data, as recently reviewed. There are many potential benefits. While I tend to focus on weight loss and type 2 diabetes, there are many other benefits, including autophagy (a cellular cleansing process), lipolysis (fat burning), anti-aging effects . . .
What is autophagy? The word derives from the Greek auto (self) and phagein (to eat). So the word literally means to eat oneself. Essentially, this is the body’s mechanism of getting rid of all the broken down, old cell machinery (organelles, proteins and cell membranes) when there’s no longer enough energy to sustain it. It is a regulated, orderly process to degrade . . .
What’s the difference in power between fasting and LowCarb High Fat (LCHF)? Sometimes it feels like arguing whether Batman or Superman is more powerful (Superman, of course). But they’re both superheros, and the point of both these dietary superhero regimens is to lower insulin. This stems from a rational examination about the causes of obesity and type 2 diabetes.
Perhaps one of the most common questions we get is what the difference is between calorie restriction and fasting. Many calorie enthusiasts say that fasting works, but only because it restricts calories. In essence, they are saying that only the average matters, not the frequency. But, of course, the truth is nothing of its kind.
How do you reign in hunger? We all think that eating more will prevent hunger, but is this really true? This is what is behind the advice to eat 6 or 7 times a day. If you can prevent hunger, then you may be able to make better food choices, or eat less. On the surface, it seems pretty reasonable. . . . [A]ppearances can be deceiving . . .