FEB 28

12. FEB 28

Assigned Work

• Kessler, The End of Overeating, Chs 1-3 (p. 3-17) (14)
• Gordon Shepherd, Neurogastronomy Chapters 11, 18, and 19 (24)

In-Class

• More on Bread in the Food budget.
• Small Group Discussion of SW2: Assessing Industrial Food Systems

Kessler, The End of Overeating, Chs 1-7 pp. 3-45

• Some comments about approaching "unhealthy eating patterns" (expand list), some baseline data, and Kessler's basic theory.

C1

• obesity trend of the 1980s. by late 80s 1/3 of pop bt. 20 and 74 overweight. (2017: 42.4% obese (note: not just overweight). J

• Historic comparisons: 1960-2000, average weight of women in their 20s goes from 128 to 157. Also other deciles. Data also revealed that some people were gaining a lot more than the average. In other words, the distribution was changing. Overweight people became disproportionately overweight. More outliers.

C2

• obesity is the result of eating too much food. Confusing to separate metabolism, etc. People underreport consumption. Studies to support claims. P.8 [Note some criticisms here: microbiome effects. Others argue that metabolic changes do occur to make significant weight reduction difficult.]

• Homeostasis: tendency of body systems to maintain bodily states within a particular range of variation. Communication occurs throughout the body to this end. But homeostasis can’t explain weight gain. Homeostasic system can be overwhelmed by the “reward system”. Anticipations of reward motivate exertion.

• Some animal studies show direct stimulation of reward seeking behavior. Stimulate the far-lateral hypothalamus” and animals overeat. Even to cross electrified floor. [Note basic explanation here.]

• Can some kinds of food stimulate us to keep eating?

C3

• Palatability - def. a food with an agreeable taste, but in food science - a food that motivates more consumption.

• Palatable foods engage sugar, salt, and fat, but also sensory cues. Research (13) on combined effects of sugar and fat (Drewnowski). Underlies many palatable features of food. Combinations of fat and sugar chosen over other mixes. Can make food hyperpalatable. Example of "hyper-palatability" in industry and as a research concept in food science.

• 15: Research (rat study) showing that consumption of SFS optimized foods increases further consumption. Both obesity prone and obesity resistant rats over ate high SF foods.

• Sclafani research. Neat fruit-loop lab detail. Just chillin' with his rats.: feeding rats a supermarket sample of palatable food makes them obese.

• Some palatability research not in the reading:

• Can the Palatability of Healthy, Satiety-Promoting Foods Increase with Repeated Exposure during Weight Loss?

C4

• examples of foods that layer S F and S. (Gordy's lemon chicken, much like p. 20 "Chicken Pot Stickers")

• reports from food execs confirming that industrial food design focuses on highly stimulating and palatable foods. Common popular restaurant foods described in terms of stacking fat on fat on sugar on salt on fat, ... etc. fat with a little lettuce!

C5

• critical of “set point theory” more interested in version he calls “settling point” theory. A kind of equilibrium between appetite (which both a drive to eat and capacity to be satisfied and expenditure - physical work and body that burns calories effectively. Constant access to highly palatable foods drives up settling point. (Kind of acknowledges that there is wide variation in the hold (capture) of high SFS foods.

• p. 25: Discussion with other people who find weight control challenging. note descriptions. Important qualification: Food cravings are not unique to overweight people. Significance of this section, I think: Most of you probably don't have similar reactions. His point.

C6

• rewarding foods are reinforcing. Reinforcing measured by willingness to work for substance and whether other stimuli can become associated with it. (Mention Neurogastronomy coming later to show how this works.)

• food can be an effective reward even in the absence of hunger. Animal studies to show this.

• “conditioned place paradigm”. — tendency to prefer the location in which a reward was experience.

• Other influences: portion, concentration of rewarding ingredients, variety.

C7

• Neural account of high SFS / palatable foods. Neuron encodes when it fires more often from a stimuli. Complex patterns can be encoded from food experience.

• Taste is predominant. “Orosensory self-stimulation”. Opioid circuitry stimulated by food. P. 37: mechanisms of the reward system. Imp of nucleus accumbens.

• Claims there is a mutually reinforcing effect between highly palatable foods and opioid circuits.

• Some evidence (Wooley p. 38) that highly palatable foods interfere with or override taste specific satiety (a mechanism that should reduce the reward experience of food at margins), which predicts that we will get tired of a single taste more quickly than if other tastes are present. Stimulation of the opioid circuits in animals overrode boredom with single taste.