Eat This Newsletter 278: Eat well
Hello
A little late this week so that I can bring you the latest results on ultra-processed foods without breaking an embargo.
Ultra-processing does matter
People lose weight twice as quickly when they eat minimally processed foods (MPF) than when they eat a nutritionally similar diet of ultra-processed foods (UPF). That’s the headline conclusion of a study from University College London, just published in Nature Medicine. This is the first study to compare the effects of MPF and UPF on the same individuals.
A total of 55 people were divided at random into two groups. One group received the MPF diet for eight weeks, followed by four weeks of “washout,” eating their normal diet. After that they ate the UPF diet for a further eight weeks. The other group started with UPFs and switched to MPFs. Both diets were tailored to reflect the UK’s Eatwell Guide, but while the MPF version might contain overnight oats for breakfast and spaghetti bolognese from scratch in the evening, the UPF version would offer breakfast oat bars and a lasagna ready meal.
The diets were matched for fat, saturated fat, protein, carbohydrate, salt and fibre and offered plenty of fruit and vegetables too. They were delivered to the participants, who were allowed to eat as much or as little as they wanted.
The researchers measured many biomedically important variables and also weight, although the participants did not know that weight was what the researchers were primarily interested in. Participants also noted their food cravings at various times during the experiment.
All participants lost weight over the eight-week period, but the loss was almost twice as great on the MPF diet compared to the UPF diet, 2.06% vs 1.05%. That may not seem like much, but over the course of a year would add up to 13% for men and 9% for women eating MPFs, vs 4% for men and 5% for women eating UPFs.
The other health-related biomarkers did not differ according to diet, but eight weeks may not be long enough to reveal any changes that are the result of how the diet is prepared rather than the overall contents of the diet.
As for cravings, people eating MPFs craved foods less often and were better able to resist those cravings, especially for savoury foods, than people eating UPFs “despite,” as the researchers point out, “greater weight loss on the MPF diet that might ordinarily be expected to lead to stronger cravings.” I expect manufacturers of ultra-processed foods will be congratulating themselves on that result.
It’s particularly interesting that merely following the Eatwell Guide results in weight loss, no matter how the diet is constructed. The policy changes called for by some of the researchers — warning labels, marketing restrictions, progressive taxation and subsidies — aim to reduce “environmental drivers of obesity” and thus to make it easier for people to choose to follow the UK’s national diet guidelines. They might even work.
You don’t say
If people in England can lose weight just by following national dietary guidelines, how about in America? It’s hard to know whether to be surprised, but the diets of 86% of Americans do not meet dietary recommendations.
Marion Nestle comments on a large study that compared what people recall eating with the Healthy Eating Index and linking that to measures of health. Nestle summarises the findings thus:
Compared to adults with high diet quality, those with very low diet quality consumed:
Less unprocessed or minimally processed foods, fruits, vegetables, whole grains, and seafood
More ultra-processed foods, refined grains, and red and processed meats
They also were more likely to be overweight, have lower HDL cholesterol, but higher triglycerides, fasting glucose, and hemoglobin A1c (a marker of type-2 diabetes).
The study currently exists as a preprint that has not yet been accepted for a peer-reviewed publication, but Nourish Science, co-founded by one of the researchers, offers more details.
The secret of greater food productivity
Hannah Ritchie is someone whose work, mostly for Our World in Data, I value enormously. She also has her own newsletter, which this past week offered an exemplary look at data rather than half-remembered factoids to make a crucial point: No, growing more food does not mean we always need more and more inputs.
Many advanced economies, perhaps most surprisingly China’s, are now producing more food with lower inputs of land, labour, and fertilisers and pesticides. Ritchie explains carefully the trajectory that agriculture seems to follow as countries develop economically. At first, agricultural outputs increase because more inputs are being brought to bear on food production. Eventually, though, better technology, better education, and some farm consolidation make the use of inputs more efficient, which manifests as more food produced despite declining growth in inputs.
That does not mean that low-income countries can immediately focus on efficiency gains to improve farm outputs; they still need to use more inputs in the short term. But Ritchie is optimistic.
By drawing on lessons and technologies from other countries, they can probably go through the “rise-peak-fall” pathway faster, and at a lower peak, than others, but zero growth in important inputs like fertilisers and irrigation seems unlikely.
Well worth reading the original.
Magic Beans and more
From europeana comes a sweet little roundup: Fairy tale food that looks at “challenge, transformation, risk: the role of food in fairy tales”. I don’t have much to add and given that the site is all about European digital cultural heritage it would be churlish to complain that there is but a single story from elsewhere. Of course, a treasure trove of other, similar articles is readily available online.
Morganatic potatoes
Once upon a time, around 8.5 million years ago, a bee visited a tomato. Its fuzzy body got dusted with pollen, which the bee carried to a neighbouring flower, only the bee made a mistake. This was not a tomato flower, but a potato flower, and from this accidental union (which might have happened the other way round) sprang “the humble modern-day potato”.
That’s the thrust of a new paper in the journal Cell. The potato in question was a species of Etuberosum, whose scientific name tells you does not produce tubers. The modern potato famously and deliciously does, and it took a mixture of Etubersum and tomato genes to give it that ability. The tomato provided a gene called SP6A that triggers tuber growth, while another gene, IT1 from Etuberosum, controls the growth of underground stems.
There are two good accessible accounts of the paper. One, is a long and somewhat rambling article from CNN. (“[T]he temple rainforest of Chile”??? SRSLY???) The other, from Botany One gives the straight facts.
Take care
