Tag Archives: food

Background Noise and Taste Perception

It has been suggested that the physiological effects of pressurisation are responsible for the blandness of in-flight airline meals. However the real reason behind “diminishing gustatory food properties” (food tasting rubbish) while 32,000 feet above sea level could be a lot simpler: the background noise.

A study conducted by Unilever R&D and the University of Manchester has shown that the background noise experienced while flying reduces the perception of food properties not related to sound (saltiness, sweetness, etc.) while simultaneously increasing the perception of food properties related to sound (e.g. crunchiness)–in other words, the background noise we experience while flying could be responsible for the food we eat being tasteless but crunchy.

On possible future applications of the findings, the BBC reports:

“We are still at an early stage of proceedings and this is a relatively small study to really draw definitive conclusions from […] but they suggest that the retail sector could well tailor their choice of food for a given environment.”

Also in the group’s findings there is the suggestion that the overall satisfaction with the food aligned with the degree to which diners liked what they were hearing – a finding the researchers are pursuing in further experiments.

Sweetness and the Problem with Diet Sodas

The link between the sweetness of a food and its caloric content may be a trait that our bodies have evolved to recognise. By disrupting what could be a “fundamental homeostatic, physiological process” by using artificial sweeteners, we could be promoting obesity.

That’s the conclusion Jonah Lehrer draws from a study that looks at how sweet tastes may be used to regulate our caloric intake and the adverse effects of diet sodas.

Adult male Sprague-Dawley rats were given differential experience with a sweet taste that either predicted increased caloric content (glucose) or did not predict increased calories (saccharin). We found that reducing the correlation between sweet taste and the caloric content of foods using artificial sweeteners in rats resulted in increased caloric intake, increased body weight, and increased adiposity, as well as diminished caloric compensation and blunted thermic responses to sweet-tasting diets. These results suggest that consumption of products containing artificial sweeteners may lead to increased body weight and obesity by interfering with fundamental homeostatic, physiological processes.

Blood Sugar and the Depletion of Self-Control

Self-control is a finite resource, goes the ego depletion theory, and through various means can be “used-up”. What, exactly, depletes and builds this resource isn’t fully known but a number of studies have shown some intriguing correlations with blood glucose level (explaining, possibly, the cookie self-control study).

The abstract of a study by Roy Baumeister summarises the findings nicely, showing clearly the possible importance of keeping a moderate blood sugar in order to maintain self-control:

Past research indicates that self-control relies on some sort of limited energy source. This review suggests that blood glucose is one important part of the energy source of self-control. Acts of self-control deplete relatively large amounts of glucose. Self-control failures are more likely when glucose is low or cannot be mobilized effectively to the brain (i.e., when insulin is low or insensitive). Restoring glucose to a sufficient level typically improves self-control. Numerous self-control behaviors fit this pattern, including controlling attention, regulating emotions, quitting smoking, coping with stress, resisting impulsivity, and refraining from criminal and aggressive behavior. Alcohol reduces glucose throughout the brain and body and likewise impairs many forms of self-control. Furthermore, self-control failure is most likely during times of the day when glucose is used least effectively. Self-control thus appears highly susceptible to glucose. Self-control benefits numerous social and interpersonal processes. Glucose might therefore be related to a broad range of social behavior.

via Hacker News

The Evidence on Breastfeeding

In an article the Royal Statistical Society announced as the runner-up in their annual Awards for Statistical Excellence in Journalism, Helen Rumbelow thoroughly investigates the well-debated subject of breastfeeding.

The conclusion of the piece is that much of the evidence in support of breastfeeding is massively misrepresented or inherently flawed.

“The evidence to date suggests it probably doesn’t make much difference if you breastfeed.” […]

“The conclusion is that the evidence we have now is not compelling. It certainly does not justify the rhetoric,” [American academic Joan Wolf] says. The problem with the studies is that it is very hard to separate the benefits of the mother’s milk from the benefits of the kind of mother who chooses to breastfeed. In the UK, for example, the highest class of women are 60 per cent more likely to breastfeed than the lowest, so it is not surprising that research shows that breastfed infants display all the health and educational benefits they were born into. But even if education, class and wealth is taken into account, there is known to be a big difference between the type of mother who follows the advice of her doctor and breastfeeds, and the one that ignores it to give the bottle. In other words, breastfeeding studies could simply be showing what it’s like to grow up in a family that makes an effort to be healthy and responsible, as opposed to anything positive in breast milk.

This is not to say that breastfeeding is not good:

  • Wolf acknowledges that it helps prevent gastrointestinal infections (life-saving in the developing world, generally a mild complaint in the West).
  • Michael Kramer (one of the world’s most authoritative sources of breastfeeding research; advisor to the WHO, Unicef and the Cochrane Library) believes:
    • The evidence is “encouraging” in preventing respiratory problems.
    • The data on helping prevent breast cancer is “solid”.

However:

  • The data on obesity, allergies, asthma, leukaemia, lymphoma, bowel disease, type 1 diabetes, heart disease and blood pressure are “weak” at best.
  • The “highly respected” American Agency for Healthcare Research and Quality (AHRQ) warns that, “because the breastfeeding mothers were self-selecting, ‘one should not infer causality'”.
  • The World Health Organisation’s own research review concluded that gains were “modest” and also warned that “because none of the studies it looked at dealt with the problem of confounding, the results could be explained by the ‘self-selection of breastfeeding mothers'”.

via @TimHarford

Seven Threats to a Sustainable ‘Food Future’

In a hugely captivating and comprehensive look at the food supply chain in Britain, Jeremy Harding provides a look at “the future of food and its supply”–including food ethics, food security and the dire need for a sustainable future.

Harding’s case is the most cogent I’ve read and it offers much more than a condemnation of our current, unsustainable habits: the article focuses on what Harding dubs the “seven big stories”–the seven fundamental “looming threats” we must keep in mind when planning for a sustainable, efficient and secure ‘food future’.

  1. Population growth: The expected large-scale urbanisation of the future “poses big questions about land use (housing v. farming) and the production of food by a minority for a majority as the gap between the two gets wider”.
  2. ‘The nutrition transition’: As we move further away from a diet based on grains, pulses and legumes and toward one of meat and dairy (the transition from maize feeding us to maize feeding the animals) means that “global production of food – all food – will have to increase by 50 per cent over the next 20 years to cater for two billion extra people and cope with the rising demand for meat”.
  3. Energy: “The industrial production of food is sure to become more expensive as fuel costs rise. It takes 160 litres of oil to produce a tonne of maize in the US; natural gas accounts for at least three-quarters of the cost of making nitrogen fertiliser; freight, too, depends on fuel”.
  4. Land: “The amount of the world’s land given over to agriculture continues to grow, but in per capita terms it’s shrinking. As with oil, it’s possible to envisage ‘peak food’ (the point of maximum production, followed by decline), ‘peak phosphorus’ [and] ‘peak land’: the point at which the total area of the world’s most productive land begins to diminish (soil exhaustion, climate change) and marginal land comes up for reassessment”.
  5. Water: “Worldwide, one in three people face water shortages and by 2030 the ratio will have narrowed. […] Much of our fruit and veg comes from water-scarce countries and […] lack of water closes down food production and livelihoods”.
  6. Climate change: “Extreme weather events will […] jeopardise agriculture and the movement of food from one place to another”.
  7. Agricultural workers: More than half of the world’s 1.1 billion agricultural workers” own neither land nor machinery and live in a state of semi-slavery. The conditions of this new global underclass are at last a matter of concern: worldwide food production is set on a downturn as their wretchedness weakens their capacity to produce and earn, driving more people inexorably towards the cities.

I suppose you could call these the food equivalent of Jared Diamond’s twelve problems of societal sustainability.