How good is Slim Sip?

New Year’s resolutions to lose weight mean TV adverts for dietary supplements like Slim Sip (glucomannan). What is the evidence it helps?

A 10-day supply of Slim Sip costs £15 and is advertised with the claim “Glucomannan contributes to the reduction of body weight in the context of an energy-restricted diet”. Does Slim Sip work?

The claim was approved for glucomannan itself (i.e., not the Slim Sip brand in particular) by the European Food Safety Authority over half a decade ago. How effective is glucomannan?

The applicants seeking approval helpfully suggested 6 studies to consider, to which EFSA added another 3 (none of which showed a statistically significant effect).

The largest study EFSA considered (just 62 participants, in 2005) showed 23 people taking glucomannan dropped an extra 1.3kg over 5 weeks. Not bad.

But by 2008 a meta analysis of 14 relevant trials covering 531 participants found an average weight loss of 0.79kg over 5 weeks.

And the latest 2014 meta analysis of all studies to date showed an average weight loss of only 0.22kg (treatment duration not stated, assumed circa 5 weeks) and considered it to not be statistically significant.



On that basis Slim Sip costs £200 per additional kg dropped.

ps the most recent study on glucomannan weight loss I can find implies Slim Sip would help shed an extra 0.03kg over 8 weeks.

pps Slim Sip is drunk with water (otherwise it’s dangerous) before eating. However, just drinking water itself before eating however has been shown to lead to weight loss, so I do wonder how much of the praise for it is due to this appetite suppression effect.


Nature of the firm

A fundamental change over the 20th century, paraphrased from a Paul Graham article:

In the early 20th century, big companies were synonymous with efficiency, as compared to delivering a product using a network of cooperating companies.

Today computers enable far easier coordination, reducing the transaction costs that Coase argued are the raison d’etre of corporations.

Peak worker

The ratio of global worker:dependant has passed a local maximum:

Percentage Population Working Age


BBC’s misleading Tax Credit graphic

The BBC currently use this graphic in Tax Credit articles:

Tax Credit Impact Chart by BBC

The middle-earning couple are NOT better off due to changes in the Tax Credit system, it has no impact on them whatsoever, so the chart title is deliberately misleading.

The low earning single parent needs to do an extra 20 minutes of work per day to avoid being worse off financially (that’s merely an observation of the mathematics, not a suggestion or endorsement of the policy change).

Give me some sugar

Can you see what is wrong with this graph?

sugar consumption per person uk

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A couple of stats

I went to a brunch briefing recently, titled ” The Future of Europe: An Investor’s Guide” where I was especially impressed with one of the panelists, Louise Cooper. A couple of her observations struck me:

  • The effective average retirement age in France is 59; in Japan it is 69
  • £100 invested into the FTSE 100 in 1984 would be £1,500 in 2014. However, if the money was only kept in the market on the up days, it would be worth £124tr now. So take with a pinch of salt claims of being able to time the market.

Peak online dating

According to several sites, today, the first Sunday in January, is the busiest of the year in online dating.

You might try (Disclosure: I’m on the company’s advisory board). It’s similar to Tinder in that you easily sign up with your Facebook account and when there is a mutual interest only then does the site facilitate messaging. The clever bit is that the profiles that get suggested to each other are where there is already a mutual friend in common (who doesn’t need to be a member of the site). This nudges it away from “hook up culture” to more genuine and meaningful interactions.

If you’re a guy, use a profile picture where you look away from the camera and don’t smile:

Male dating profile picture advice

If you’re female, “selfie above the head” shots are best:

myspace2 myspace1

Or have a bed in the background. Men are like that.