Welcome to the continuing diary series "Let's Read a WHEE Book Together!" Today, we're continuing with David Kessler's The End of Overeating, with diaries generally appearing on Tuesday mornings and Saturday afternoons. If you're just discovering this diary series, you will find the previous installment by Edward Spurlock here, and he -- very helpfully -- provides links to other previous installments at the bottom of his diary.
Chapter 10, "Cues Activate Brain Circuits That Guide Behavior" returns to the role of dopamine in hooking our attention and energizing our activities. As we learned in Chapter 8, dopamine means motivation.
WHEE (Weight, Health, Eating and Exercise) is a community support diary for Kossacks who are currently or planning to start losing, gaining or maintaining their weight through diet and exercise or fitness. Any supportive comments, suggestions or positive distractions are appreciated. If you are working on your weight or fitness, please -- join us! You can also click the WHEE tag to view all diary posts.
Nature shoots us a shot of dopamine when we get an unexpected reward, such as a surprise squirt of sweet, tasty juice. In the process, our brains learn – both at the conscious level and at the neurological level, as Pavlov’s dogs and rat studies have abundantly shown.
The brain catches on to cues that, next time, signal to it that a reward is coming. These cues, not just the reward itself, can exert tremendous power.
In the lab, a cue is usually a light or a tone. Outside the lab, clicker training for animals is an example.
Food rewards are good for training, but
the reinforcement must happen AS the behavior is occurring, not afterwards. The actual reinforcement can't always be gotten to the animal at that precise instant, however. Trainers needed to find another way of letting the animal know that he was doing the right thing, so they began using a conditioned reinforcer.
That is, a cue. Clicker training is being recommended not only for dogs but for cats and horses. And, reportedly
At least one study has shown that the clicker can reduce training time by 1/3.
In our daily lives, food cues as well as actual foods can similarly motivate our impulses.
And like clicker-trained animals, we learn fast. Kessler describes how test subjects got high sugar, high fat snacks at a particular time each morning for five mornings. The next morning, they automatically experienced a desire for such foods at the same time. The test subjects never needed such snacks at particular time before, but a habit and a felt need were already established – that easily.
Kessler writes, "Cues ensure that we will work hard to obtain the reward."
An environmental cue that a rewarding food is on its way stimulates dopamine. Dopamine strengthens our motivation. Related neurons fire like crazy. We feel desire. We are motivated. If we obtain the reward, our brain experiences a delightful shower of pleasure chemicals -- opioids -- and still more dopamine...so we tend to keep eating.
This sequence is not necessarily a problem. Where calorie- and nutrient-dense foods are a rarity, it’s a key survival tool.
And the sequence is not necessarily a problem for everybody even in a milieu packed with cheap, high-fat, high sugar convenience foods. In spite of this pervasive environment in the U.S., about one-third of U.S. adults are still able to maintain "normal" weight, according to the CDC.
With at least some of us, however, cues signaling a food reward can entrain our behavior even against our conscious will. In the words of Harvard neurobiologist Steven Hyman, "The pursuit of reward tends to proceed to completion despite obstacles and distractions."
The facade of the local pizza restaurant...the bright packaging that signals and conceals our favorite snack food...odor of frying bacon...the buzz of conversation around side tables offering pastries before the opening session of a professional conference...the sensory overload of an amusement park or fair...lights, music, greenery, and the regular social gatherings of the holiday season...
Kent Berridge, at the University of Michigan, has suggested that some people are more vulnerable to the "incentive salience" of food cues – i.e., pick food cues out of the background more quickly, experience them more vividly, and are more highly motivated by them.
There is indeed some evidence of individual differences in reactivity:
...18 obese and 18 normal weight, otherwise healthy, adult females...participated in an eye-tracking paradigm in combination with a visual probe task...Obese individuals had higher scores than normal weight individuals on self-report measures of responsiveness to external food cues and vulnerability to disruptions in control of eating behavior. Both obese and normal weight individuals demonstrated increased gaze duration for food compared to nonfood images in the fasted condition. In the fed condition however, despite reduced hunger in both groups, obese individuals maintained the increased attention to food images, while normal weight individuals had similar gaze duration for food and nonfood images.
At the same time, I wonder if a fairly high reactivity to food cues is particularly pathological.
Considering that two-thirds of U.S. adults are now overweight or obese, perhaps in this environment, only those with less-than-normal interest in food are able to maintain a "normal" weight?
Food porn coming right up! After the housekeeping:
Upcoming diaries: comment to the tip jar to reserve your spot - WHEE depends on your participation to keep going!
Tues PM - Sychotic1
Weds AM - Edward Spurlock
Weds PM - ???
Thurs AM - A DC Wonk
Thurs PM - ???
Fri AM - ???
Fri PM - ???
Sat AM - ???
Sat PM - Edward Spurlock (Kessler, Ch. 11)
Sun AM - louisev - Turtle diary
Sun PM - ???
Mon AM - NC Dem
Mon PM - ???
Tues AM - Clio2 (Kessler, Ch. 12)
Tues PM - ???
And just to kill any remaining appetite:
Bacon ends lack natural cohesion when cooked in a pattie or other similar form. The invention involves grinding or chipping the bacon ends, and adding to the bacon end pieces a meat addition which is high in protein content, an edible food substance which is high in albumin content, and a protein filler. Water also is added, and the above are mixed and shaped into a suitable form, while maintained at a temperature in the range of about 10° F. to about 45° F. The amount of meat addition, albumin containing food substance, and filler added to the bacon end pieces is sufficient to prevent disintegration of the food product during cooking.
Whew! At least that particular food cue should never trouble us again!