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.