What are the *risks* of losing weight (when overweight)?

This posts relates solely to people who are overweight or obese and who have excess weight to lose. Those who are at a healthy weight have different risks from losing unnecessary weight.

Edit: 30 May 2025 - nice article by Bethany Brookshire in Scientific American, New powerful GLP-1 drugs drop a lot of weight fast. How does that affect health? (About the effects of weight loss, particularly dramatic loss, on muscle and bone).

Edit: 29 June 2025 - I suppose enough people have recently been losing weight with the various Mounjaro / Ozempic type drugs for this question to be updated.

I've not heard of any additional atherosclerotic risks from people losing their excess weight. This could be because

• There is no additional atherosclerotic risk from losing weight
• The risks have not yet been reported or have not been specifically linked to the weight loss
• It's still too soon for any additional atherosclerotic risks to become apparent.
  

There may be other risks / side effects (adverse effects) from using these medications but this post is solely about the resulting loss in bodily mass arising from any method used to lose weight (fat).

Original post

I've sent an email to the World Obesity Federation to ask. My sciencey background never brought up this facet of weight gain / weight loss but I have occasionally wondered. 

If transporting fats around the body when putting on weight can lead to atherosclerotic damage and high blood pressure can't the same thing happen when losing weight as, from a 'transport infrastructure' point of view, there's no difference - fat, in the form of lipoproteins, is whizzing around in the blood whether it's about to add to or be taken from adipose tissue.

Here's what I sent, if I get a reply I'll add the gist of it.

I am trepidatiously adding 'weight loss' to the labels for this post, knowing that this will very effectively bring a lot of spam commenters to my yard ;)

•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

Hello :)

I'm curious to know about the risks of losing weight (the benefits seem fairly obvious). As a fat person I have plenty of fat stores, which initially grew because fats (directly or derived) from my diet would have been transported around in my blood and eventually stored in various adiposits. Presumably some will also have been laid down atherosclerotically en route. Bummer. I expect we'll find out in a few years. Probably not that many as I'm 51.

If I begin to lose weight wouldn't the exact same process happen in reverse? A bit of metabolism will free up some of my lard which will then lipoprotein its way around my bloodstream before eventually being breathed out as CO2. Presumably in doing its circulatory rounds some of it could also contribute further to any atherosclerosis.

So is losing weight quite a dangerous undertaking? Prevention certainly better than cure I suppose.

Also, would I then flood my system with all the fat-soluble vitamins? Not too bothered about D or K, but I might want to avoid self-overdosing on Vits A And E. Presumably there will be other fat-soluble things that pop out into my bloodstream, much like a molecular version of ancient mammoths being released from the melting permafrost.

My retweet of a tweet in a thread by Foone about composting the
rich, rather than eating them (Compost the rich, don't eat the rich)

Presumably in returning to my bloodstream these fats will make it thicker and stickier, adding a blood pressure risk to weightloss proceedings. Possibly one should lose weight very slowly. Or maybe take blood thinners while doing so.

I'd also presume that the relative risk weighs (ha!) more in favour of losing any excess weight but I don't think I've ever seen this aspect of risk considered. 

Can you point me to any research in this area (I have a degree in biochemistry* and have worked in a lipid chemistry lab so am comfortable with academic literature).
 
Thanks
Jo

*Pedantically my degree is B.Sc (Hons) Combined Studies because that's what the modular degree was called (you could also do Combined Arts). My degree is in Biology, Psychology and Computer Science. I then did a Masters degree in Neuroscience. Given that neuroscience kinda covers biology, psychology and computer science you might imagine some great intentional plan but no - entirely by accident. I don't think I'd even heard of the word neuroscience until graduating and someone suggested it as a (suddenly rather obvious) follow-up.

Online talks coming up this week (science heavy)

Lockdown has not interfered that much with my hobby of attending science talks - hooray. 

Here are a few coming up that I might well go to. 

Wednesday 31 March
•  Botany in 18th Century Cambridge: A first look inside the Martyn collection - 4pm - FREE  
•  Into the London Fog - 6.30pm - FREE

Thursday 1 April
•  Overloaded: how your brain chemicals influence your life - 12.30pm - ~£20 
 - from the Royal Institution (Eventbrite events)
•  Bats in Churches - 6.30pm - FREE 

Sunday 4 April
•  In Conversation with David Attenborough - 2pm - FREE 

Wednesday 7 April
•  RECOVERY trial, one year on - 9am - FREE 
•  Colonial Knowledges: Environment and Logistics in the Creation of Knowledge in British Colonies from 1750 to 1950 - 5-6pm - FREE
This one is fairly academic: "The effects of colonial power dynamics on knowledge creation in the long nineteenth century and beyond are well known and have become the foundation of a postcolonial reading of British scholarship in the context of empire. What has been less well examined are the practical effects of the colonial context on knowledge making. This seminar series seeks to explore how logistical and practical factors, such as the physical environment including climate and distance from the metropole, influenced the creation of both scientific and humanistic knowledge in British colonies."

Jo's list of useful events pages (most are, like me, in London)

• Alan Turing Institute
• Barbican
• BCS (British Computer Society) 
• Blackheath Scientific Society
  
• British Library
• British Museum
  
• Cadogan Hall 
  
• The Charterhouse
• Centre for Research in Digital Education (Edinburgh)
  
• The Cinema Museum 
• Conway Hall
• Eventbrite - search, random cool stuff pops up 
  
• Faber members (email list) 
• Friends of Tower Hamlets Cemetery Park
• Frontline Club
• Gresham College 
• Hampstead Scientific Society
• Highgate Literary & Scientific Institution 
  
• Horse Hospital
• Kennington Bioscope
  
• Kew Gardens - events 
• Kew Mutual Improvement Society (Kew Gardens)
  
• King's College London 
• King's Place
• ICA
  
• In The Dark Radio
  
• The Last Tuesday Society
  
• Linnean Society
  
• Lost Lectures
• Magic Lantern Society
• National Theatre
• Natural History Museum
  
• Neal's Yard Dairy (cheese-themed classes!) 
• QMUL - Public Lecture Series
• Quarantine Book Club (US, online)  
  
• RA (Royal Academy of the Arts)
• Richmond Scientific Society
  
• Royal Albert Hall
• Royal Geographical Society
• Royal Institution
  
• Royal Museums Greenwich
  
• RSA
  
• Royal Society of Medicine
• Science Museum  
• South London Botanical Institute
• The Social
• Satellite (art) 
• V&A - Victoria and Albert Museum 
  
• Worshipful Society of Apothecaries
  

 

 

 

 

 

The Imaginary Paddington 2 Science Festival

Following on from my Imaginary Maritime Science Festival (full of good ideas even if I say so myself) I have begun thinking about the science in Paddington 2 and what my imaginary science festival based on it might look like. Pretty good actually. Give my (slightly stretched) links between the film and science listed below a hard stare and see what you think.

1. Andean spectacled bears 
2. Oranges...
3. ...and marmalade
4. Botanical art
5. 3D representations: Origami
   
6. 3D representations: rendering of images in computers
7. Robotics
8. Facial recognition technology
9. Steam trains
   

1. Andean spectacled bears
Paddington's look is based on a real bear, Tremarctos ornatus (spectacled bear) - they're rather cute. I think there could be a lecture about their lifestyle and habitat, conservation efforts and so on, and relationship with other types of bear.

2. Oranges...
In 2007 I spent a happy fortnight at the University of Leiden studying on their Economic Botany course (ethnobotany with a particular focus on how humans use plants). Much like dogs plants are bred for all sorts of reasons and when it comes to fruits it's things like flavour and peelability. The citrus family is full of created fruits with a long lineage from ancestral forms of deliciousness. While studying there I managed to get to eat a few of the more unusual ones (it was a wonderful and fascinating course, led by David Mabberley).

3. ..and marmalade
Plenty of science in marmalade making - role of pectin, extractions and filtering, flavour molecules, sterilisation of glass bottles etc. Perhaps there could be a workshop in which everyone gets to go through the process of making marmalade and then takes home a jar of marmalade. Depending on how long the process takes that bit may involve pre-made marmalade.

4. Botanical art
This would possibly fall in the Arts & Crafts section of the festival (which, by the way, is interdisciplinary) as this obviously involves drawing - but it has been an important tool in scientific understanding and discovery and was incredibly important before photography got underway. Herbaria are library collections of dried plants (herbarium specimens) and are beautiful, if sometimes a little eerie.

An interesting aside is that paintings made of Primula flowers a century before Darwin described the two different forms (thrum and pin) showed these features very clearly. There is also an archaeobotanist who has used renaissance art to uncover lost species of fruits.

5. 3D representations: Origami
There's a lovely bit in the film when Paddington imagines his aunt Lucy seeing a pop up book of London (first video) and I think we might have a nice session on the science of folding and space-saving. For example the second video shows a foldable solar array for use on space satellites (I think there's similar stuff going on with antennae too, which can be folded for launch and unfurl once in orbit).

 

 

6. 3D representations: rendering of images in computers
The wonderful Framestore once came to QMUL's computer science department to give a talk about their work on the film Gravity. Normally these talks are tolerably well-attended, this one was packed with people turning up all the time trying to squeeze in. It was also the same day as the Christmas Party so normally people would have been happy to bring things to a rapid conclusion and get to the beers and wine but we all cheerfully kept the Framestore chaps for an hour and a half pelting them with questions about how they'd done all this amazing stuff in computers. They also did the fantastic Visual Effects (VFX) for Paddington 2 and you can see some of their work in the video below.

 

7. Robotics
A bit more tenuous but there will be people who could talk you through what it would take to 'animate' one of the bins at Paddington station and have it wheel around the concourse thanking anyone who drops something in it.

8. Facial recognition technology
Phoenix Buchanan spends most of the film trying to disguise himself as different characters so that he can get close to various London landmarks without suspicion to collect a variety of letter clues deposited on them (these are to be played as musical notes on a fairground organ which will unlock it, letting the player access the treasure within). At 1m 33s in the video below Mrs Brown is having tea with Phoenix Buchanan and, alerted by his comment about a pencil drawing having blue eyes, realises that he is the thief as all the images of him drawn for the wanted posters suddenly overlay over his eyes. It reminds me of a scene in the film Amelie in which she makes a discovery (don't watch the video if you've not seen the film as it will spoil things for you).

There could be an interesting talk about facial recognition technology, how it's been used and misused - how biases in algorithms can hurt some sections of society in particular - and how some (though not all) police forces have stopped using it.

 

9. Steam trains
Slightly more tenuous but the Brown's son Jonathan is particularly keen on them and learns about them in his holiday, putting this knowledge to good use at the end of the film. Lots to be said about steam power, from a historic point of view too, and here are some fabulous photos of exploded boilers. Yikes.

 

 

 

 

Invitations to book for an NHS Covid-19 vaccine may come from "accurx.thirdparty.nhs.uk" and are legitimate

tl;dr - the NHS is using "accurx.thirdparty.nhs.uk/r/" to send out invitations to book Covid-19 vaccines and the link is genuine. At the end of that link you'll have your own 10 digit unique code (don't share that publicly).

https://accurx.thirdparty.nhs.uk/r/ - enter the 10 digit code you receive in your text message, book your vaccination - get injected and protected, not infected :) Continue to be careful afterwards as you can still get Covid-19 though it is likely to be less severe and I think you can still transmit even if you're not affected.

 

The Salisbury Homeopathy College appears to have shut its doors

Salisbury #Homeopathy College is apparently permanently closed (hooray) & no longer accepting applicants. Its website still implies that it's courses are accredited by the Society of Homeopaths but the Soc has already removed it from its own list of accredited course providers. pic.twitter.com/sVtbgMSixb

— Jo-nuary Blues 🌊 ❄️ (@JoBrodie) February 7, 2021

It's always cheering news when something comes to an end in the world of homeopathy. We've seen University courses close, websites taken down or amended, and of course the numbers of homeopathic items prescribed on the NHS have been dropping precipitously for a couple of decades (it's still clinging on though). 

Recently things have taken an even worse turn for homeopathy with bad news for homeopaths appearing in newspapers every few months, following a series of undercover reporting finding homeopaths making misleading claims and offering fake treatments or preventatives.

In January this year the Society of Homeopaths (SoH) lost its accreditation from the Professional Standards Authority (PSA). The PSA was concerned that the SoH had failed to prioritise public safety over the interests of its members and suspended accreditation, to be reviewed in one year. 

The Salisbury Homeopathy College was one of several colleges to have a course accredited by the SoH, which keeps a list of accredited courses on its website. This listing appears to have been removed some time after October 2020, though the College's own website still carries SoH logos and the suggestion that its courses are accredited. 

However it appears that the Salisbury Homeopathy College has now permanently closed. Its website says that it's no longer accepting applicants and its listing on Google indicates closure beyond mere opening hours. I don't know why it's closed or when that happened, but sadly the SoH still lists plenty of other places which will charge people fairly large sums of money (several thousand) to teach them nonsense. 

You can read about one skeptic blogger's visit to the College on its open day in 2018. One of its courses cost nearly £10,000 - I'm amazed its former students don't sue.