Tuesday, August 5, 2014

More on Cravings Research.

There is much confusion about cravings, it is time to do some reading and clipping.

http://science.howstuffworks.com/innovation/edible-innovations/food-craving.htm   says  most revolve around the hedonic, or pleasurable, aspects of dining [source: Hill] so off I go to Hill.
Hill, Andrew J. "The psychology of food craving.

http://journals.cambridge.org/download.php?file=%2FPNS%2FPNS66_02%2FS0029665107005502a.pdf

Hill does not accept food addiction. OK. Hill goes on to suggest that cravings are cognitive / emotional, not physical / chemical. He suggests that it is craving mainly are for highly palatable foods. Boredom and stress make cravings worse. OK.

Does this mean that cravings would reduce if I only ate palatable food. We would need a palatablity scale, un, low, medium, high, hyper. So no high or hyper palatable foods. Is satiation related to palatablity in an inverse fashion? No, enough, enough, more, please more, for a direct inverse related satiety scale. So if cravings are hedonic, if I only east low and medium palatable food I will not crave or crave less? Is that what you are suggesting, Hill?  I will need to test that a bit before I swallow that. It could be all shit.

Experts believe that cravings occur for a variety of reasons. They attribute them to evolution, psychological factors such as stress and unhappiness, and  -  sometimes  -  a genuine need for certain foods.

from source noted below
'It's crucial to remember that a food craving is not simply hunger,' says Professor Andrew Hill, Head of the Academic Unit of Psychiatry and Behavioural Sciences at Leeds University.
Hunger is the body's way of making sure it is provided with energy, in the form of nutrients from food. When the stomach is empty, it releases the hormone ghrelin, which communicates with the brain's command centre, the hypothalamus. This creates the feeling of hunger and is how we know when to eat.
Satiation is signalled by the release of the hormones leptin by fat cells, and insulin by the pancreas, in response to increased blood sugar.
Cravings, however, are much more complex.
'Those who are starving will eat literally anything  -  even foods they do not enjoy  -  to stay alive,' says psychologist Dr Leigh Gibson, Reader in Biopsychology at Roehampton University.
'Cravings, on the other hand, are an overwhelming sensation of desire for a certain food. There are a number of chemicals in the brain that are associated with this.
'First, there is dopamine, a brain chemical that is involved in learning and concentration. When we see or experience something new, dopamine is released in the brain.
'This works in tandem with other brain chemicals called opioids, which give us feelings of enjoyment and pleasure. The combination of these two factors mean that the brain associates certain activities with pleasure, and it teaches us to do them again and again.
'From an evolutionary point of view, junk food cravings are linked to prehistoric times when the brain's opioids and dopamine reacted to the benefit of high-calorie food as a survival mechanism.
'We are programmed to enjoy eating fatty and sugary substances, and our brains tell us to seek them out.
'Today, we still have the same chemical reactions to these so-called hyper-palatable foods, causing an unignorable desire  -  despite there being less of a nutritional need for them.' 

Also note that when insulin is high, we cannot see leptin. Lustig says it is insulin molecule blocks the leptin receptor. 
Also note that sugar and fat we needed to survive better long term. Those who ate sugar and fat stored a bit more energy for the lean time. Those of us that fatten easily and have those cravings had a better chance of survival... but not in time of plenty. We just crave and get fat, fast or eat only low palatability foods for a while, and the excess should go away, as long as we can avoid the cravings.

more from above


The body produces a hormone called cortisol in response to stress,' explains Dr Gibson.
'Its primary functions are to increase sugar in the blood to be used up as energy by the body's cells, suppress the immune system and aid in fat, protein and carbohydrate metabolism. It also blocks the release of leptin and insulin, increasing hunger.
'This is why studies have shown that when we're stressed, we're more likely drawn towards high-energy foods, such as cakes and sweets. Stress in response to danger used to mean energy was burned up. Stress down to today's lifestyle may have the same effect, though these days we are less likely to actually burn off the calories.'
Then there are the psychological components to cravings.
'Mood is unquestionably a potent context  -  especially negative mood,' says Prof Hill.
'We crave reward foods. The pattern for this is partially set in childhood when parents give us sweet food to show love or reward.'
Anna Raymond, of the British Dietetic Association, agrees.
'Cravings are a psychological need for high-fat and high-sugar foods which taste pleasant  -  but which should, of course, form only a small part of our daily intake.'
Dr Gibson points out that sweet food can actively alleviate pain by releasing opioids, thus excusing us for giving sweets to a hurt child. Researchers at the University of Michigan found that chocolate causes the brain to release these euphoria-inducing chemicals.
Unsurprisingly, more than 50 per cent of reported cravings are for chocolate and most others are for highly palatable foods such as sweets or biscuits.
'Chocolate melts at body temperature which gives a pleasant sensation, and fat and sugar further increase the sensory appeal,' says Prof Hill.
Gender can influence the nature of cravings. According to Prof Hill, studies show that women predominantly crave sweet, fatty and energy-dense food and men have more savoury cravings, although it is not yet understood why. 

So what does all this mean? We have a number of potential cause of cravings:
  • Cognitive 
  • Physical
  • Environmental
  • Maladaptive or emotional, stress
  • food addiction - food chemical induce
And after the craving is a space, where it should be forced through the cognitive processes before we react to any craving.  
In the words of Victor Frankl: "between stimulus and response there is a space. In that space is our power to choose our own personal response and in that response lies our growth and freedom."  




1 comment :

  1. more papers to read thanks could be helpful
    Josh

    ReplyDelete

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