Veganuary and Bad Science
In the beginning of February 2018 a news article spread in the UK media claiming that only a quarter of UK evening meals contained meat or fish due to the meteoric rise of vegan and vegetarian diets. Extraordinary claims require extraordinary evidence but upon reading the first few sentences of the articles it becomes clear that some very pertinent information is either misinterpreted or noticeable by its absence. Let’s take a look at the chronology of the story.
The earliest reference I can find to this information, which also seems to be the main source of the articles, is a commentary by the Kantar World Panel, a UK consumer panel, from February 5th which analysed the shopping habits of 30,000 households during the 12 weeks prior to January 28th. I quote from that commentary directly:
“…: “As consumers look to more healthy alternatives following the holiday, trends like Veganuary have taken off and now 29% of evening meals contain no meat or fish at all”. This sustained interest in vegan and vegetarian diets is reflected in the chilled aisles — over January one in ten shoppers bought a meat-free ready meal, causing sales to rocket by 15% compared to this time last year. Sales of spinach, cherries and aubergine also grew strongly compared to the past 12 months — up 43%, 25% and 23% respectively.”
It’s very reasonable to assume that consumers are looking for healthier alternatives after the holiday season. Besides, dieting and gym subscriptions see a similar rise in popularity during the first weeks of a New Year. And it does follow that these behaviours give birth to trends like Veganuary and that interest in healthy eating during January is common. But you can’t call such situations “sustained” if they only occur once a year. A sustained action is one that carries on without interruption.
Furthermore, as is previously mentioned in the same commentary, shoppers spend less money during January compared to the preceding holiday season. Healthy eating is undoubtedly the noble pursuit at the centre of the process of buying vegetables but it must be said that vegetables are a lot cheaper than meat. The economic justification shouldn’t be separated from the nutritional one when we’re talking about money.
The select choice of ingredients is also strange. I couldn’t be happier for spinach, cherry and aubergine farmers but there is no mention as to the welfare of the potato, lettuce and cabbage farmer. Meaning we are not presented with the full picture. For all we know every single other vegetable and fruit may have seen a decrease in sales.
The commentary is specific to mention that it is evening meals that don’t contain meat or fish. I would be curious to know what breakfast and lunch looked like in the households in question. From my personal experience my family and friends frequently overcook and ‘overfreeze’ turkeys and briskets and chickens and sausages and shanks and loins during the week up to New Year’s Day, leaving everyone plenty of leftovers to experiment with new recipes for sandwiches and curries.
On February 6th, Daily Mail seems to be the first of the major outlets to write an article about these results. Quoting from the article:
“During January, one in 10 shoppers bought a meat-free ready meal, leading sales to rocket by 15% compared with the same time last year, while 29% of evening meals are now free of meat or fish, the latest grocery market share figures from Kantar Worldpanel show.
The “sustained interest” in vegan and vegetarian diets also saw sales of other fruit and vegetables grow significantly on this time last year, such as spinach, cherries and aubergine, up 43%, 25% and 23% respectively.”
What we see here is a game of Broken Telephone unfolding. Whereas the original commentary is careful to mention at the very beginning that the results were obtained based on shopping habits during the 12 weeks up to January 28th and that the decrease in meat consumption occurs after the holidays, in the Daily Mail post the 12 week period is mentioned further on but in relation to another statistic. Moreover, if you hadn’t read the original source you would be right to conclude that evening meals have changed forever. Not to mention that you would assign a desire to buy spinach, cherries and aubergines as stemming from a sustained — meaning continuous and unending — interest in veganism and vegetarianism, not from the influence of prices or a possible surplus in those ingredients.
From the BBC article:
“In the 12 weeks to the end of January, 29% of them [evening meals] contained no meat or fish, according to Kantar Worldpanel.
Trends like Veganuary (going vegan for January) and “sustained interest” in meat-free diets are affecting habits, the market researcher said.”
Here, the change in habits during January have been extended to the whole 12 weeks! In addition, the second quoted sentence makes no sense. The habit of eating healthier after the holidays created the interest in vegetarian meals, not vice versa.
The other articles contain similar errors that I won’t break down here for the sake of brevity. Safe to say the whole picture would have presented the reader of such articles a skewed view of reality. The misinterpretation of results which occurs consistently in the science and health columns of UK media outlets is so profound that even 29% is rounded down to 25% (a quarter) instead of up to 30% (3 in 10).
I urge the careful and critical reading of articles which contain statistics but if ever in doubt, send them my way. See you in the trenches!