MAR 14

14. MAR 14

Assigned Work

• Kessler, Chapters 27-32, p.(137-165) (28)
• Rolls, Barbara, "The Role of Energy Density in the Overconsumption of Fat," American Society for Nutritional Sciences, 2000, 246-253. (7)
• Notice of "Heavy Reading Days" coming in later March. Please read ahead over break.

In-class

• Harold McGee.
• Burkhard Bilger, "Can Babies Learn to Love Vegetables?," New Yorker, Nov 25, 2019 (12)
• Tarragon & Moreno, "Role of Endocannabinoids on Sweet Taste Perception, Food Preference, and Obesity-related Disorders" Chemical Senses v. 43, 3-16, 2018. (13)

Harold McGee

• Father of Neurogastronomy - gastronome who knows science. [1]

• Two main works: On Food and Cooking and Nose Dive

Kessler, Chapters 27-32

27

• major claim: hyperpalatable foods don’t just change behaviors, but rewire our brains.

• effective rewards change our feelings (Kagan 138). Reinforcement learning does this.
• memory enhances futures to cues. “Cue-urge-reward-habit”
• intense stimulants create desires for more.

28

• phen-fen - discountinued drug combo — increases serotonin, decreases dopamine response (reward response). Obesity patients reported dramatic change in susceptibility to food cues.

29

• Claim about mechanisms for conditioned hypereating: cues - priming - emotions.

• Cues: images (commercials, product packaging), routines (driving by a drive through). Thought elaborates the cue - “elaborated thought” (may include recollection of good feelings, rationalizations, embellishments).
• Priming: eating a bit primes our hunger — study at 149: test subjects given specific primes (pizza or ice cream), when presented with both after eating one or the other, eat more of the one they already ate.
• Emotions: “emotional eating” - brain imaging study - after inducing a negative mood in some subjects, greater activity in reward areas to anticipated milkshake. Stress also, but profound stress can dampen reward circuits.

30

• Having developed a conditioned response to hyperpalatable foods, thought suppression often fails to limit desire. “White bear problem”

31

• Major claim: conditioned hypereating is a syndrome - condition related to cluster of symptoms and effects.
• ”disinhibited patterns of eating” - snacks, evening a nighttime meals, “continuous eating”. Willingness to “work harder” for food.
• Reno Diet Heart Study — reanalysis of a 1985 large longitudinal study of obesity and heat disease. But the survey instruments contained items related to conditioned hypereating (159). Reanalysis showed correlation with obsess participants.
• Dana Small neural imaging co-research with Kessler: people scoring high on factors of conditioned hypereating showed neural response (including amygdala) from smell and flavor cues.

32

• ”Externality theory” 70s theory — Schachter cracker study (!): thin and overweight test subjects eat sandwiches, some don’t, some fill out survey about food (priming). Result: thin sandwich eaters eat fewer crackers and thin non-sandwich survey takers (no surprise), but overweight sandwich eaters eat more cracker whether or not they ate sandwiches first. Hypothesis: visual cues more powerful for overweight.
• Similar results from Nisbett’s roast beef sandwich study.

• But then, 1981. Judith Rodin critiqued externality theory, with “restraint theory” — idea that differences bt people with or without food control was “restraint” or will power difference, not a conditioned response to food. Restraint theory tells you that you just need more willpower to change your diet.

Rolls, Barbara, "The Role of Energy Density in the Overconsumption of Fat,"

• The nutrition rock star herself. [2]

• [Framing the problem: Our evolutionary challenge, under typical conditions of more frequent food insecurity, is to seek energy (calories). In Kessler's theory, this explains the greater sensitivity of the reward system and neural response to hyperpalatable foods. Rolls is looking at the same mechanisms, but by comparing energy dense and nutrient dense foods.]

• Energy density theory - High energy dense, low volume foods cause lower levels of satiety than nutrient dense foods of similar palatability. Or, diff macronutrients have different consumption patterns and satiety effects.

• Pre-load studies - test subjects are given food before a meal time (the pre-load) and then mealtime consumption is observed. Pre-loads that reduce voluntary consumption are inferred to have greater satiety.

• Back to "Does fat make you fat?" - Maybe the energy density of fat, like the density of highly palatable foods, makes you less satiated, but it's not the fat itself that is less satisfying, rather the energy density (aka ratio of volume/cal). Old idea: fat has a unique ability to make you fat. But these studies did not control for the confounding effect that energy dense foods have less weight and volume that nutrient dense foods. So we drew the wrong conclusion: fat makes you fat. Rather, all energy dense foods have higher ratios of calories to volume. You are sated by volume.

• New research, when controlled for energy density, fats and carbs have similar effects on satiety (measured as subsequent food intake after a "pre load" of some food under study). So, "fast carbs" and fats have similar effects. It's not fat that makes you fat, it's palatable, energy dense foods -- because they are less stating, we eating more of them. Another way to put it is that we eat for volume.

• water as beverage vs. water in foods (as in youtube) - Casserole v. soup study water study. Added volume from water in soup reduced subsequent intake, but not if water was present as a beverage.

• 269S: studies suggesting that we eat by weight, not by energy intake. So the same amount of food by weight, if energy dense, will increase our calorie intake.

• Note: High volume, high nutrition, low density foods are typical of humble cuisines. Grains, legumes, water filled vegetables.

Burkhard Bilger, "Can Babies Learn to Love Vegetables?

• 1st theme: The Good Tastes Study - Susan Johnson U of Col. pediatrics. Baby taste tests.

• 2nd theme: Calvin Schwabe - veterinary epidemiologist UC Davis. Unmentionable Cuisine . We're omnivores. We're passing up alot of food, like cats and beetles. In a sense we are our tastes -- supertasters, low tasters/high sugar preference. Julie Menella from Monell Chemical Senses. omnivores/brain plasticity (recall Shepard)

• 3rd theme: Saskia Sorrosa, CEO of Fresh Bellies -- Ecuadoran, didn't like baby food options for her daughter. Represents traditional cuisine argument for baby food (at the end of the article you get another example): babies eat adult foods, specially prepared. Palette Training - [interesting idea that our palattes are trained, even before birth, and in early childhood (Mennella - everything gets through to the fetus). Possibly the same systems and mechanisms as you would encounter in changing your diet (we are all Judge 7). Fresh Bellies is doing very well (new food economy!) Their formula: no added sugar, natural (acid) preservation instead of industrial pasteurization. 3x price (maybe another 50 cent egg lesson?)

• baby food industry back story -- 9 billion - mostly fruit and sweetened vegetables. Amy Bentley, Inventing Baby Food. Before vitamin discovery, veggies seen as source of illness due to unclean conditions.

• 1921 Harold Clapp, first baby food. Some details there. 1969 baby food scandals - contamination and research on rats showing hypertension from baby food. 1/3 of baby food homemade.

• 4th theme: Inside Gerber's baby food testing facility. 2/3 market share! "baby black ops site". Judge #7. Baby sugar bliss points are twice adults. From 1970 - 2000 childhood obesity tripled. 7 month-olds drinking soda. Gerber adds fruit to everything, not added sugar anymore. [But what sort of palette training is fruit and veg? Or yours? How does your diet train your palette?]

• Palette training claim: it takes 10 tries. Most parents give up after 3-4 tries.

• New industrial baby and early childhood foods in development. More squeezable tubes for delivery.

• 5th theme - from baby food to military foods (big theme in food nutrition awareness historically was from military preparedness. Many battles lost to scurvy and malnutrition). How fighter pilots eat.

• Closing scene at African market in Maine. How people from non-industrial cuisines feed their babies. But you have to have a cuisine to do this. Americans have an "interrupted cuisine"

Tarragon & Moreno, "Role of Endocannabinooids on Sweet Taste Perception, Food Preference, and Obesity-related Disorders"

• You could work from the abstract on this one. I just wanted you to see some technical research to balance the Nyer article. Also, the research paradigm in this article connects with the "conditioned hypereating" theory of Kessler and depends upon findings in neurogastronomy.

• Summary: Claims that highly palatable food is part of obesity problem. References mechanisms of food choice: reward system, environmental cues, internal factors. The article is a literature review of: 1. research on how our food tastes emerge and get fixed, especially sweet taste; 2. how genetics, experience, lifestyle, etc. influence palette; 3. the role of the "endocannabinoid system (ECS)" in setting the palette.

• Some highlights: research on parallel between food cravings and drug cravings (also in Kessler and Shepard). Details of sweet receptors (recently found in the gut, adipose tissue, and the brain, as well). There is a genetic dimension to sweet taste perception. p. 4 - people with particular alleles of the T1R genes have greater sweetness discrimination (note, they may have a more multi-sensory experience of sweetness). (table 1 summarizes some of this research).

• ECS (endocannabinoid system) - mechanisms. [Digresssion: From wiki page on ECS: "A related study found that endocannabinoids affect taste perception in taste cells[60] In taste cells, endocannabinoids were shown to selectively enhance the strength of neural signaling for sweet tastes, whereas leptin decreased the strength of this same response. While there is need for more research, these results suggest that cannabinoid activity in the hypothalamus and nucleus accumbens is related to appetitive, food-seeking behavior.[57]"

• eCBs are synthesized as part of the chemical system that gives us hedonic responses from food. Example practical studies: Argueta p. 6. "Dysregulation" of the ECS is related to decrease in pleasure from food. Some research, p. 7, on effects of high O6/O3 ratios on ECS. Connections also between ECS and inflammation, depression.

• from conclusion.