Question: a couple of friends have jumped on the Intermittent Fasting bandwagon and asked me to read a book by Dr. Jason Fung, MD, watch a couple of movies on the topic. One thing Dr. Fung brings up: with dieting, your metabolism is lowered for months or years if you lower your caloric intake. Studies, research, et al, are cited. With IF, and in some examples IF combined with a higher fat diet, metabolism remains the same or increases per Fungās references, the MDs in the movies, etc.
Anybody can cite studies to prove pretty much anything.
So that in itself is meaningless.
To lose weight you have to create a caloric deficit , irrespective of the diet used (including Dr Fungās).
Doing so in isolation will lower the basal metabolic rate. A major reason for this is that some of the weight lost will be muscle tissue.
That is one of the key reasons why Dr Darden has promoted progressive high intensity weight training for so many years.
Not only do his clients not lose muscle on a diet , but they actually gain muscle , thereby boosting ones metabolic rate.
There are of course other things to take into consideration, but in simple terms the best way to lose fat is to create a caloric deficit , and to progressively lift weights.
I tried IF for a while. I became dehydrated. I thought I was drinking enough water. My kidney function decreased to disease levels.
I know this because I get bloodwork a few times a year. My doctor sent me to a nephrologist.
I had to make a few changes. Limit caffeine. I stopped red meat. I went back to drinking lots of water along the lines of what Dr.Darden recommends.
My kidney function is back to normal now.
I donāt care what any possitive research says. No way would I use IF again.
The key to any diet is stick to something that is sustainable.
Did you ever notice people with low body fat that are ripped? Who say that is because they IF.
Both the brain and muscles preferably use carbohydrates as the primary fuel. A high carbohydrate diet with calorie control (or restriction) works. Why interfere with the normal bodily functions? I rest my case. Eat your breakfast!
The question was on lowering your calories and the long term affect on your metabolism based on the results of multiple, fairly large studies and research.
As long as you lift weights in a progressive way and keep away from extreme/fad diets , then any reduction of metabolic rate will be small and short lived.
Mark/Dips - That is still not what is being asked in my post to Dr. Darden. The science cited by Fung (and I also believe work with his own patients) and others stated:
Extended caloric reduction via a ādietā = slower metabolism.
Intermittent Fasting = No reduction in oneās metabolism, better insulin sensitivity, more optimized periods of autophagy + growth hormone + glucagon.
Dr. Darden does advocate a low caloric intake in his books via 3x meals + 2x snacks/day, superhydration and HIT ā with lots of emphasis on negative training. The reduced calories is for periods of six weeks.
āthen any reduction of metabolic rate will be small and short lived.ā
According to multiple sources cited by the authors, videos, etc., Iām referring to, this is not correct. I can try to find their references and post them. Would be interested in your references or work in this area?
I am not a scientist.
I have trained people and given them diets ,I have competed in bodybuilding numerous times and have helped others with their prep.
At no stage has there ever been a problem noticed with anyones metabolic rate.
In fact when I was at my leannest ever in 2012 ,I increased calories , got even leaner and gained 2 pounds for my next contest (without any "assistance ").
In regards Dr Fungās claims , I consider them complete BS.
His views on nutrition are certainty not mainstream (which in itself does not make them good or bad,. But it is important to mention that) and are carefully selected and often taken āout of contextā to āprove his pointsā
I donāt have any issue with IF , but I do have with many of the unproven claims of superiority of it. by some of its supporters.
These represent my own views from 38 years of being involved with exercise and nutrition.
I used to be a late night eater, but it started to get to my stomach. So, I donāt eat 4-5 hours before bedtime which means I go about 12-13 hours a day āfastingā. Maybe even 14 hours on weekends. I did lose weight this way without trying. However, I also drink a lot of water throughout the day and still pack in enough calories during the day.
I was watching Joe Rogan who had Ronnie Coleman on recently. Ronnie said he used to wake up in middle of night to eat and go back to sleep during his competitive days. lol I cannot imagine.
I used to do that no food after dinner routine because heard that that food mostly turned to fat but I found after doing that I would wake up early and not get enough sleep. It seems my body type needs some carbohydrates before bed.
Scott
Neither am I a scientist. Iāve read various books, papers, etc., and have been my leanest on a diet around 50% carbs, 30% protein, 20% fat. Also helped others while I was in the military get ready for team qualifcation, annual testing. Got in shape for some endurance events, did well. Did compete in a bbāing contest once ā mediocre genetics ā so one and done.
Regarding Fung, Iād suggest calling them āclamsā is a misrepresentation ā if you havenāt read his references and work with his patients, then, I donāt understand how can dismiss them as BS.
Yet you note youāre not a scientist or MD (nor am I), but, said there has never been a problem with anyoneās metabolic rate. So assuming, you didnāt take bloodwork? Test factors that determine an individualās metabolism before/after?
And Fungās āviews on nutritionā --he does encourage low carb, but, he also states in one of the books I read whole/complex carbs such as legumes are acceptable. But, he is very, very much against fructose and processed carbs ā especially fructose because of its affect on the kidneys to include inflammation and other issues (heās a nephrologist). Not mainstream, for sure, as it goes against the Standard American Diet.
If you havenāt read his books (have read three loaned me), watched his videos (also a couple of movies heās in such as Fasting on Prime), etc., your statements appear to be misrepresenting Fung (and other MDs) regarding his information and recommendations.