New Year, Less Flab: Well, it's that time of... - Weight Loss NHS

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New Year, Less Flab

TheAwfulToad
TheAwfulToadAmbassador
30 Replies

Well, it's that time of year when we'll all be making New Year resolutions (and then promptly forgetting about them :) ). There's been an upsurge in posts concerning low-carb (LCHF) recently, so if you're thinking of giving this a go after your holiday indulgences, herewith a short FAQ ... and a bit of mythbusting.

There is so much misinformation written about LCHF that many people who believe that they're "doing low-carb" or "going keto" are actually not. There are many ways to get low-carb wrong (the first few weeks are particularly critical). However, if you get it right, everything just drops into place.

What is LCHF?

It stands for "low carb high fat", but it's a bit of a misnomer. You'll certainly be reducing your carbs close to zero in the first two weeks, and adding quite a lot of fat, but after a few months the macronutrient profile will change, and your meals will not look radically different to anyone else's. You'll be eating a varied diet with lots of vegetables, nuts, some fruit, and a modest amount of animal protein if that's your thing. All the things that the experts say are good for us.

What is a "keto" diet?

Your body has many different possible fuel sources - some are derived from your diet and some are synthesized internally. They're all in use at any given moment, but your dietary habits will alter the ratio in which they are used. A "keto" diet is one which is very low in carbs, forcing your body to use mostly fat for fuel, which it burns in the form of acetoacetate or beta-hydroxybutyrate (ketones), fatty acids, or glucose,after performing various conversions. Unlike LCHF, a keto diet demands strict adherence to a low carbohydrate intake at all times.

My nutritionist says that all bodies need glucose, and if I don't eat carbs I'll die.

The nutritionist is wrong (most nutritionists are, most of the time). It's true that human bodies need some glucose, but carbs (starches) are not the only source. A fat molecule (a triglyceride) is built on a glycerol backbone, which your body can convert via a simple chain of reactions into glucose. Every fat molecule that's released from bodyfat storage undergoes this process; that is, every fat molecule delivers three fatty acids, and half a glucose molecule. Most of your body's organs can burn the fatty acids directly, or after conversion to ketones. Excess amino acids (typically liberated from cell reconstruction processes) are also converted to either ketones or glucose.

The only hard requirement for glucose comes from your brain, blood cells, and corneas, amounting to few hundred kCal per day.

So a low-carb diet causes fat-burning?

It's a bit more complicated than that. It's true that low-carb diets cause your body to rely heavily on fat for energy, but that isn't the primary reason why your bodyfat reserves become depleted. It's more accurate to say that, when you're eating adequate fat and minimal carbs, your body has no need to maintain a large mass of bodyfat. One of the functions of bodyfat is to buffer the large, uncontrolled power surge from a meal heavy in refined starches, so when you stop eating such things, your body has no need for all that bodyfat, and it will start to discard it.

I don't want to eat more fat. Fat causes heart disease.

It's depressing that this myth refuses to die. It just stumbles on like an ideological zombie, refusing to accept that its head has been cut off, and propelled along by nothing but voodoo. Nobody has yet pinned down what causes heart disease, but one thing now seems fairly clear: it's nothing to do with fat, saturated fat, or cholesterol. Interestingly, what put the final nail in the coffin was a series of scientific trials on drugs which either reduce total cholesterol (statins),reduced LDL (statins and PCSK9 inhibitors), or increase HDL (statins and niacin). All of them do exactly what they say on the tin. Unfortunately, what they don't do is have any effect on either heart disease or total mortality - in fact several of them caused additional deaths in the intervention arm of the trial. Ooops.

On the other side of the coin, millions of people are now eating LCHF diets, and steadfastly refusing to develop heart disease - in fact they're generally much healthier than people eating the Standard Western Diet, as well as being slimmer. The nutritionists call this a "paradox". Scientists call it "disproof".

What's the difference between LCHF and Atkins?

Not a lot. The main ones are:

a) Atkins went a bit overboard on his carb restrictions. His prescription for induction was basically spot-on, but he was incorrect about the general ability of humans to tolerate carbs. The vast majority of people can eat quite a lot of carbs - at least if not eaten at every meal - without gaining weight.

b) He suggested eating protein "ad lib", and many people thought this meant "eat as much meat as possible". All he actually meant was that you don't need to measure it. LCHF discourages excessive protein, for various boring reasons.

How do I do this right?

You'll proceed in two distinct phases - induction and weightloss. "Maintenance" is considered a third phase, but it's really a continuation of the second; you don't have to think about switching from "weightloss" to "maintenance" because it just happens all by itself.

In the first stage you'll go keto. You eliminate all visible carbs from your diet and add fat to your meals in quite large amounts; any source is acceptable, but highly-processed vegetable oils are best avoided (canola, corn, etc). Most people find the best way to do this is to add lots of vegetables with fat-based sauces or dressings; for example, by roasting vegetables in olive oil and butter. You can also add dairy fats ad lib to (for example) scrambled eggs, or coffee. Milk should be avoided at this point, but cream and Greek yoghurt are fine. All low-fat food substitutes should be avoided!

There is no need to add extra protein. You might find you're eating a little extra meat as you consume extra meat fat, but it's unlikely to be very noticable.

After a while you'll simply get sick of adding fat to your meals. This typically coincides with the onset of fat loss - you'll probably see it happening in your face any belly before it registers on the scales. Your appetite will drop and you will naturally dial back on the butter, cream, etc. Congratulations, you're now in the weightloss phase. This will continue for several months, during which time you'll feel inclined to add back the occasional dose of carbs (such as fruit or a slice of wholemeal bread), and there's nothing at all wrong with that.

How do I do it wrong?

There are unfortunately several ways to mess this up:

- Trying to substitute more protein instead of fat.

- Not eating enough vegetables (if you do this your meals will be unpleasantly greasy, and you may not get adequate micronutrients).

- Not recognising where the carbs are lurking; root vegetables and fruit are common culprits, as are things-in-packets that purport to be "low sugar" but are still very high in starches.

- Trying to do low-salt while on low-carb. Contrary to popular opinion, most people are eating too little salt. If you experience muscle cramps or weakness, you may have inadequate salt intake.

- Trying to count calories. You eat when you're hungry, and stop when you're full. Under no circumstances should you attempt to control your portions. Let your appetite tell you when enough is enough. It may get things a bit wrong for the first day or two, but it'll rapidly sort itself out.

For those who are interested, there's a group for LCHF:

healthunlocked.com/lchf-diet

But as you may have noticed, many of the members here are doing some variant of low-carb. Because it works.

30 Replies
oldestnewest
moreless
morelessAdministrator

Many, many thanks Toad, this is a brilliant post and I'm sure it will help many people.

I'm going to pin it, so that it doesn't get lost and link it to other similar posts that we have.

Thank goodness we have people like you that are able to explain the science in layman's terms :)

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TheAwfulToad
TheAwfulToadAmbassador
in reply to moreless

Thanks moreless! I tried to boil it down to the bare essentials. We seem to get occasional upsurges in interest in LCHF, with the same questions being asked, so hopefully this will be of use to newcomers.

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moreless
morelessAdministrator
in reply to TheAwfulToad

Oh absolutely! I see this being rolled out all the time. You may get fed up with having to reply to everyone :)

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telute
telute2st 7lbs

It is worth noting that if you're doing lchf the different types of fat do affect the health benefits/risks involved.

There's a layperson round-up of the differences by Harvard med here - health.harvard.edu/staying-...

While the evidence for saturated fat causing heart disease isn't strong- the evidence that replacing it with polyunsaturated fat helps reduce risk is pretty good so it's worth bearing in mind when doing lchf

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TheAwfulToad
TheAwfulToadAmbassador
in reply to telute

I think it's one of those esoteric debates that's best avoided because it invariably descends into a Holy War, but notice that that page restates the same tired old meme:

"A diet rich in saturated fats can drive up total cholesterol, and tip the balance toward more harmful LDL cholesterol, which prompts blockages to form in arteries in the heart and elsewhere in the body."

Not one word in this sentence is true.

Firstly, as noted, the statin trials definitively disproved the idea that LDL or cholesterol is the proximate cause of heart disease. Many of these drugs lower LDL by 30, 40% or more. If you use sensitive enough statistical tests, you can tease out a tiny positive effect on CVD for statins, but not for other cholesterol-lowering drugs; their effect on CVD is a rock-solid zero (although some of them cause different diseases, driving up total morbidity/mortality). The only possible conclusion is that statins achieve the effect that they do via some mechanism other than cholesterol-lowering, and there are various theories about this (eg., enhancement of nitric oxide synthesis, or anti-inflammatory effects).

The basic idea here is that cholesterol is some nasty gunk that oozes around uncontrolled, greasing up the works. It is not. It is an important structural molecule that (like everything else) is sent out into your bloodstream with a specific intent, and packaged up in such a way that it cannot go where it's not wanted. It gets picked up and recycled by structures designed to do such things. At no point does it just float around, wedging itself into your arterial endothelium and causing "blockages".

If we were to accept for a moment that the cholesterol theory were actually true, then reducing cholesterol by 30% would not actually do much good; your blood is, after all, circulating around and endlessly replenishing whatever is taken out at the capillaries. If this were a purely mechanical silting-up of the arteries, you would expect a 30% reduction in LDL (or whatever) to simply delay arterial blockage, not prevent it; to get any noticeable effect, you'd have to eliminate all cholesterol. That would indeed eliminate the possibility of heart disease, because you'd be dead.

Secondly, progressive "blockage of the arteries" is not a huge problem. Every aged corpse on the autopsy table shows some degree of arterial blockage. It's normal. Where things go horribly wrong is when arterial plaques cause clots, which break off and lodge elsewhere causing acute ischemia and/or infarction. Your body deals with slow arterial narrowing by constructing its own bypasses where necessary.

Thirdly, different fatty acids cause different responses in terms of cholesterol measurements; chain length seems to be of more interest to our biological processes than whether a fatty acid is saturated or unsaturated. Nobody has any idea what these differences mean. It's probable that they mean precisely nothing.

As for the issue of EFAs : these are available in adequate amounts and the correct ratio from, uh, animal fats. Particularly oily fish, which tend to feature heavily in LCHF diets.

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telute
telute2st 7lbs
in reply to TheAwfulToad

Have you got links for the statin evidence - I'm curious as the meta analysis evidence summaries I can find are generally positive so I'd be interested in where the conflicting evidence is from and how much of it there is (I'm a medical librarian so it's a professional curiosity as I don't like to be missing resources when doing research! :-))

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TheAwfulToad
TheAwfulToadAmbassador
in reply to telute

You'll get a much better view by reading the original studies - meta-analyses, by their nature, tend to discard information, which is a very bad thing indeed when the studies they draw upon are exercises in obfuscation.

Anyway, I'll root them out for you. I can't remember their names off the top of my head.

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telute
telute2st 7lbs
in reply to TheAwfulToad

Thanks - meta analysis & systematic reviews consider all studies unless there's a reason they can't be compared - in which case they'll state why a study was excluded. Often that's due to a lack of clarity around the subjects or study parameters.

I do think if we're talking about medicine rather than diets we need to cite evidence as it could be worrying to people on that medication - and everything I've found says statins are safe and effective. I wouldn't want anyone reading this thread to get concerned about taking them if they've been recommended

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TheAwfulToad
TheAwfulToadAmbassador
in reply to telute

I absolutely would want people to get worried about them, and I'll explain why when I have a moment. You're quite right that assertions should be backed up by evidence.

The main problem with meta-analysis is that you have to develop a consistent scale onto which you will drop all of your study results, in order to compare apples with apples. This is often very difficult to do, because different studies pick different endpoints according to the whim of the study designers (or, more cynically, in order to guarantee a positive result).

In fact meta-analysis is an inappropriate tool unless you're looking for evidence to formulate a hypothesis. Why? Because if any particular study was properly designed, and it produced a negative result (ie., the null hypothesis was upheld) then that result stands as valid. Nothing further needs to be done to make it more valid. If there was no effect, and the study was sufficiently powered, then there was no effect. QED, back to the drawing board.

The majority of the registered statin trials showed no effect. You are aware, I'm sure, that negative studies were and are simply buried, although less of that goes on since it became mandatory to register clinical trials with the regulatory authorities. Thus if you see a positive result from a meta-analysis done prior to about 2006-7, the most likely reason is that the meta-analysis was only able to find studies with a positive result.

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telute
telute2st 7lbs
in reply to TheAwfulToad

A meta analysis would include negative results - they're not designed to prove a hypothesis but to assess the total evidence and improve understanding by the statistical analysis of multiple studies at once.

Systematic reviews & meta analysis ate the best evidence we have (the Cochrane review on statins is here - cochrane.org/CD004816/VASC_... ) because they combine and assess the totality of the available evidence.

And really you shouldn't be scaremongering about medication

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TheAwfulToad
TheAwfulToadAmbassador
in reply to telute

It can't include negative results if they've never been published. And if you can only find a statistically-valid result by combining vast numbers of subjects, then by definition you're looking at a very small effect that may have no clinical significance, even if you've managed to achieve statistical significance. Meta-analyses have their place, but they can only be as good as the underlying data (or alternatively: garbage in, garbage out).

Do you disagree, then, that a single study that upholds the null hypothesis is valid in and of itself?

I'm not "scaremongering" here; I'm describing published data. As I said, I'll try to find you the studies I'm referring to, and we'll have another discussion about it.

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telute
telute2st 7lbs
in reply to TheAwfulToad

The point isn't that it's the only way to find a statistically valid result - a large rct will do that. The point is that by combining results of many trials you can arrive at a better conclusion - more data is better than less.

One negative trial among a hundred positive ones is clearly an outlier - so yes a single null result shouldn't negate all the positive ones unless the positive ones can be proven to be faulty in some way

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TheAwfulToad
TheAwfulToadAmbassador
in reply to telute

15 negative trials among 20 mediocre positives is a rather different proposition. That's the sort of ratio we're talking about here.

However, I would still argue that a single outlier (if the study is properly constructed) should be taken seriously, especially in the current climate when scientific fraud is accepted as normal.

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telute
telute2st 7lbs
in reply to TheAwfulToad

And I'd be interested in seeing those results as - as I've said - the evidence I can find is broadly positive.

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S11m
S11mMaintainer
in reply to TheAwfulToad

"Single studies are often duplicated - to add weight of evidence.

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S11m
S11mMaintainer
in reply to telute

Re: Cholesterol and statins:

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jubbly1955
jubbly19551 stone

Thanks TheAwfulToad, a really useful post as always.

Happy New Year. 😀

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TheAwfulToad
TheAwfulToadAmbassador
in reply to jubbly1955

Happy New Year jubbly!

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lucigret
lucigretAdministrator

A brilliant post- thank you for taking so much time to put this together and a Happy New Year to you 😊

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Lytham
LythamSuper Host 3st

Excellent post, I'm going to attach the link to my post, thanks for all the info ! :-) x

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PandQs
PandQs3st 7lbs

Hi Toad, that is such a good post that I’ve cut&paste it into an email and sent it to myself to keep. I’ve also just read a post from Drummerswidow, and replied saying she should look for your post, as I didn’t know how to link her to it.

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IndigoBlue61
IndigoBlue61Administrator

Excellent post TAT 👍. Thank you for sharing

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tubby54
tubby542019 December

Dear Toad,Thanks for that clear,down to earth,easily understandable summary of LCHF. I've saved it on my lap-top just in case I get stuck counting cals and decide to change.

Happy New Year.

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BridgeGirl
BridgeGirlAdministrator

Thanks for this, TAT. I'll save and share it :)

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S11m
S11mMaintainer

Hi TheAwfulToad...

Did you see this at the PHC conference - indicating that Low-carb is becoming mainstream?

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S11m
S11mMaintainer

Hi, TheAwfulToad, have you seen this "proof that the body has zero requirements for carbohydrate":

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TheAwfulToad
TheAwfulToadAmbassador
in reply to S11m

That's a good one. I've seen a couple of Ekberg's videos and he's generally good at explaining technical stuff for a non-technical audience. He crams a lot of useful facts into 25 minutes there, although his explanation of gluconeogenesis is a bit convoluted.

I particularly like his attitude - that human bodies are incredibly well-designed and possess multiple redundant systems and backups to make sure we keep going under all the situations nature might throw at us. This contrasts sharply with the typical medical view that all bodies are crappy Heath Robinson machines that break at the slightest opportunity, and therefore need to be dosed up with pills by doctors who, apparently, are so clever than that can improve on a million years of evolution.

I also completely agree with his statement that the best plan is to "mix it up" to mimic a seasonal diet. I've said something similar several times.

What irritates me is that there is no actual need to "prove" that humans don't need carbohydrates. Any medical textbook explains why we don't. The physiology is completely understood. It's rather mundane stuff. Yet the nutritionists still argue that black is white.

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Caroline62

Thank you for taking time in writing this post.

Please if you are able to answer I would appreciate.

Some number of years ago after stomach by pass we get told to eat low fat as now with some of the large intestine is also by passed. We get told very little fat and more protein. More lean meat to eat first then veg, Can you give any answers to this . 😊

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TheAwfulToad
TheAwfulToadAmbassador
in reply to Caroline62

Well ... my first observation would be: if bariatric surgeons knew why people get fat in the first place, they wouldn't be performing radical surgical interventions. They'd be telling people how to eat right.

"It is difficult to get a man to understand something when his salary depends upon his not understanding it."

- Upton Sinclair

It's hard to answer your question without implying that your surgeon failed all his physiology exams. I doubt this is so: it is more likely, as per Sinclair's quote, that he's simply going through the motions without questioning what he's doing.

Let me ask you a question in response: has your stomach bypass and prescription diet made your life better? Is your body now the shape that you've always dreamed of? Do you enjoy your meals?

I realise that you have gone through a very unpleasant procedure and a lot of psychological stress prior to that point. I don't want to hurt you further by pointing out that your surgeon has done something completely unnecessary to you, but that's the truth of the matter. I personally can answer "yes" to all of those questions ... and I achieved that by eating more fat and less carbs, as opposed to having a stomach bypass. I'm not unique. I'm an ordinary human being and it's worked for many other human beings. So why did your doctor not try the same thing before making irreversible changes to your internal plumbing, on the rather dubious assumption that your body was badly designed?

As regards low-fat, high-protein diets:

- All British people are now on low-fat diets. Even if they're not doing it voluntarily (many are), they don't have much choice: supermarkets have put low-fat foods on the shelves front-and-centre. You have to look really hard to find the version that hasn't had all the fat removed. Sometimes there isn't one. Yet British people are still (mostly) overweight. Clearly, then, something is amiss with the idea that "dietary fat makes you fat".

- Protein is not a fuel source for humans. We are capable of extracting energy efficiently from carbohydrates or fat. That's all. We lack the specialised metabolic pathways that obligate carnivores possess for burning dietary protein. There is no sensible reason for telling people to eat more protein.

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Tessa75

Thanks toad i found this very helpful.

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