IF vs. calorie-reduction diets and their effects on 'Set-point'' body weight

This topic contains 5 replies, has 6 voices, and was last updated by Apricot 8 years, 8 months ago.

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RobertWie

11:03 pm
8 Mar 16
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I am fairly new to 5:2, having been inspired recently by Dr Mosley’s “East, Fast and Live Longer” BBC programme and having lost many battles over the last 10 or so years trying to lose weight through self-control, exercise, calorie restriction, “eating well” and all the usual advice.

I have done a lot of research in the last few weeks on the science of intermittent fasting. I read a lot of the forum posts on this website, I watched Dr Mosley’s programme a couple of times and I read many of the blog posts on Dr Jason Fung’s IntensiveDietaryManagement.com (as clearly Dr Fung seems to promote fasting quite strongly, and his blog posts are very comprehensive with lots of data / diagrams etc. to justify his opinions).

After all my research, to date, one thing puzzles me:

What is really the difference between intermittent fasting vs low-calorie diets which clinicians tend to advise to people trying to lose weight?
More specifically, how does intermittent fasting get round the so frustrating issue of weight loss plateau experienced in all other diets, where the body tries to fight back and slow the metabolism down to prevent starvation?

Dr Fung argues that Intermittent Fasting increases, not decreases, the BMR.
He argues that unlike calorie-restriction diets, which restrict calories all of the time (and thus lower the BMR, which make those diets ineffective longer-term), fasting, according to him, has the opposite effect.

However, reading through this forum it seems that 5:2 is really just a calorie-restriction diet(though intermittent). If so, will we not have the same issue with 5:2 as we do with all other diets, whereby due to the ‘set-point’ body weight mechanism (where body will adjust the relevant hormones which regulate metabolism, hunger levels etc.) very few diets are effective longer-term, and a lot of the time people trying to lose weight regain all of the lost weight eventually, and a few pounds extra for good measure?

lucylaw

11:21 pm
8 Mar 16
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I am a lay person, but I have read a lot about this, and I think you are missing the point a little bit. The set point is a product of hormone, more specifically, insulin. As I said earlier, every time you eat, an insulin response is generated. IF, whether 5:2 or daily IF like 18:6, is designed to generate an insulin response fewer times. If you throw in low carb to help out the cause, then the insulin spike will also be reduced.

There are a lot of people here who talk about TDEE and frankly, I’m not sure that is much more than “calories in, calories out”, because metabolism is more hormonally responsive than that. Dr. Fung’s 24 part (and counting) series on Fasting will give you much more detail, and is quite science-based. He does specifically talk about body set weight in his blog post of April 4, 2015 in “Do All Diets Fail- How to Lose Weight XI.

simcoeluv

12:38 am
9 Mar 16
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Hi Robert again:

There is no such thing as ‘starvation mode’ – it is a myth. Here is Dr. M’s brief explanation: https://thefastdiet.co.uk/forums/topic/food-thought-fast-day-starvation-mode/. Your BMR is irrelevant for weight loss – it is already included in TDEE, which is the key number.

You lose weight on 5:2 via calorie restriction, just like any other weight loss diet. Your TDEE is impacted by things other than sex, height, age, weight and exercise levels like drugs, hormones, etc. But TDEE is what it is and if you eat over it you will gain, if you eat under it you will lose, and if you eat equal to it you will stay the same.

As for the set point theory, at this point it is just a theory. If you are interested, I strongly suggest you watch this BBC doc about the set point theory to understand just how complicated the issue is (it is really all about the theory, although it just mentions it at the end): https://www.bing.com/videos/search?q=why+are+thin+people+not+fat+documentary&view=detail&mid=899E9160D89B70CACB8F899E9160D89B70CACB8F&FORM=VIRE4.

So the bottom line is the less you eat, the more you lose, and you have to eat to your TDEE or less to maintain your new weight after your successful diet. Many people have lost weight, and many have maintained their weight loss.

Not that it was easy!

IveGotStitch

9:43 pm
10 Mar 16
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The quality of food being really important re set point and a lot of scientific studies support this. The Calorie Myth book by Jonathan Bailor a very good interesting and iluuminating read.

TrueMirror

6:58 pm
11 Mar 16
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Hi Robert,

I can only talk for myself and what I have read. I am not following 5:2, but EOD fasting based on Dr. Varady’s research. We can say there is scientific research behind EOD, once she spent 10 years over it. There are some key points. Your question make sense and I think you don’t confuse anything.

EOD fasting works better than daily caloric restriction. So if you follow the pattern of one day with min. calories and then you have your normal eating day, it works better than consistent low calory path. This might work as psychologically as physically. The fact you can eat without drastic restriction every other day makes miracles from psychological POV, so you “suffer” only one day and it’s manageable for human being. This is very important factor for people who cannot lose in decades.

But it works from physical POV too. After several weeks of following this pattern, your body learns how to follow your hunger. Fasting learns you to eat when you are really hungry and avoids compulsive eating. I don’t think that especially western society really knows what hunger is. They usually binge from different reasons, mostly various kinds of psychological disorders. Fasting learns your body to ask what it needs and misses.

Fasting has the benefits and you don’t need extra study about it. It’s known from historical sources since biblical times till today and some enlightened doctors will say so. During the fasting body starts cleaning process and repair it’s cells instead of producing the new ones. Constant feeding doesn’t give your body any space to start natural healing process. More fasting days better effect on your body. However you are only one person who can give the proof to yourself and don’t need any advice from the others. But weight loss is part of it, fasting body is removing garbage and fat cells contains a lot of it unlike daily cal restriction, which just slow your metabolism down and later stops to work or you will not manage it and start to cheat.

Some people here take it as calory restriction diet and forget about benefits of fasting itself. If you cannot go with 0 cal days, then try to eat your 500 cal meal after 24 hours from the last meal. Every person knows how he or she feels when they are healthy. And my experience is there are a lot of changes in my body and it’s not just due to weight loss. To answer your question there is a huge difference between fasting and simple cal restriction every day, it’s health and healthy body lose additional weight faster. The aim of fasting is to get your body into healthy mode and overweight body is not healthy.

Here you have some quotas from doctors about fasting, even if they don’t mention any research behind it, seems they know what they are talking about and you can get inspiration:

http://www.allaboutfasting.com/fasting-quotes.html

Apricot

1:27 pm
11 Apr 16
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Yes TrueMirror, and others, it is about several things. I’ve also recently read Krista Varady, Jason Fung and Dr Mattson, all of whom have done research on intermittent fasting. One plus about it is that, provided you also eat enough protein and fat and keep your exercise reasonable, you don’t lose muscle which is a problem with low cal restricted diets. This helps to keep your metabolism from slowing and protects your heart muscle. Krista Varady’s research let people eat their normal carby American diet in between – she didn’t want too many variables. But the other two included low carb, higher proteins and fats, which keeps insulin and sugars in balance.

I tried 4:3 to shift a plateau and because I’d gone over quantity slightly one day. It worked. But importantly my blood pressure is lower, my asthma is improved and although I’ve only lost 11lbs so far, my waist is 5inches less, so it’s clearly taking visceral fat.