Thursday, March 15, 2012

The Food Industry and Why It Works

I think it's safe to say that the food "industry" does not care about providing safe, nourishing, healthy food for people. It wants to fill you with cheap calories and keep you malnourished so you are hungry for more. Our inborn cravings for sugar, salt and fat are manipulated by chemically engineered foods that short-circuit our natural mechanisms for satiety and weight management. Their concerns are 1.) to make it taste good, 2.) to get us addicted and 3.) to keep us coming back for more. The only concerns are profit - not health. Release this into a society now dominated by sedentary activities like sitting at a desk all day, and you're naturally going to get a population with deteriorating health.

Walk around any supermarket and you'll see sugary sodas, candy, bakery, cookies, muffins and the like, breads and cereals and the like within easy reach. These calories are cheap: fueled by subsidized wheat, sugar, soy and corn (in the form of corn syrup), so profits are high. Couple that with incessant advertising emanating from every surface, and you see why this is the dominant food in the American diet. For most of history, food has not been an "industry" at all. Turning food into an industry is the natural outgrowth of our economic system, and its effects on human health are being felt around the world. We're living longer, but getting sicker. "Lifestyle" diseases are endemic. What can one say about an economic system where the outcomes are one in three adults will become diabetic, and even ten year-olds are having limbs amputated?

It's hard to see any realistic solution, however, short a financial collapse that takes down the food industry.

BoingBoing's been on a tear lately, with some really terrific articles. Here's one about food:

Seduced by Food: Obesity and the Human Brain
In 1840, a German doctor named B. Mohr made a critical observation while performing autopsies on obese subjects: some of them had damage in a part of the brain called the hypothalamus (B. Mohr. Wschr Heilkd, 6:565–574. 1840). Over the ensuing century and a half, researchers gradually uncovered a network of circuits in the hypothalamus dedicated to maintaining the stability (homeostasis) of body fat stores, by regulating food intake, energy expenditure, and the deposition of energy in fat tissue. This research culminated in the discovery of an extraordinary hormone called leptin in 1994. Produced by fat tissue in proportion to its mass, leptin enters the circulation and acts in the hypothalamus to regulate body fat stores. If you consistently restrict food intake, fat mass declines and so does leptin, and this signals the hypothalamus to stimulate hunger and make the body use calories more efficiently, in an attempt to regain lost body fat (4). Conversely, if you consistently overeat, the increase in fat mass and leptin suppresses appetite and increases calorie use until body fat stores have declined back to baseline (5, 6). Leptin and a few other hormones are part of a negative feedback loop that acts unconsciously to keep fat mass in a specific range, sort of like a thermostat does for temperature (7, 8). This is called the ‘energy homeostasis system’.

So if we have this built-in system to regulate body fatness, how does anyone become obese? Some researchers believe the energy homeostasis system defends against fat loss more effectively than fat gain. However, most obese people regulate their body fat just fine, but their brains ‘defend’ it at a higher level than a lean person. Going back to the thermostat analogy, in obese people it’s like the ‘temperature’ has been gradually turned up. That’s why it’s so hard to maintain weight loss—when body fat stores decline, the brain thinks it’s starving even if fat mass remains high—and it acts to regain the lost fat. If we want to understand how to prevent and treat obesity, first we have to understand why obese people defend a higher level of fat mass than lean people.
First described in 1976 by Anthony Sclafani, the cafeteria diet is basically a rat-sized buffet of human junk food, in addition to regular rat chow (9). The menu for a recent cafeteria diet study included such delectable items as Froot Loops, mini hot dogs, peanut butter cookies, Cheez-its, Cocoa Puffs, nacho cheese Doritos, cake, and BBQ pork rinds (10). These are what's known in the business as ‘palatable’, or pleasurable to the taste. On this regimen, rats ignored their regular chow, ate junk food to excess and gained fat at an extraordinary rate, far outpacing two comparison groups fed high-fat or high-sugar pelleted diets. Yes, human junk food happens to be the most effective way to overwhelm the body fat homeostasis system in rats, and neither fat nor sugar alone is able to fully explain why it’s so fattening. Importantly, over time, rats become highly motivated to obtain this diet—so motivated they’ll voluntarily endure extreme cold temperatures and electric shocks to obtain it, even when regular bland rodent pellets are freely available (11, 12).

The cafeteria diet is an exaggerated version of an unhealthy human diet, and not many people eat quite that poorly. However, have a look at the top six calorie sources in the current US diet, in order of calorie contribution: grain-based desserts (cake, cookies, etc.), yeast breads, chicken-based dishes, sweetened beverages, pizza and alcoholic beverages (13). Our eating habits aren’t as different from the cafeteria diet as we might like to believe.

To understand why junk food causes fat gain in rats and humans, we have to explore two other circuits in the brain, beginning with the reward system. The reward system acts to gauge the desirability of food (among other stimuli) and reinforce and motivate behaviors that favor the acquisition of desirable food. For example, if you eat a strong cheese for the first time, maybe it won't taste very good to you. As it's digested, your reward system gets wind that it's full of calories, and the next few times you eat it, it tastes better and better until you like the flavor (17, 18). This is called an acquired taste, and the reward system is what does the acquiring, motivating you to obtain a food it has deemed safe and desirable. This is the same process that allows children to learn to like vegetables—which are low-calorie, often bitter foods that are initially unpalatable-- if they’re repeatedly paired with fat, salt or some other desirable quality. The reward system does the same thing with foods/beverages that contain drugs, such as coffee and beer, gradually making bitter fluids palatable and then delicious.

Eventually, you may go out of your way to purchase the cheese or beer at the grocery store, and maybe you'll consume cheese or beer even if you aren't hungry or thirsty, simply because you like it. This is an example of the reward system reinforcing and motivating behaviors related to foods it considers desirable. What does the reward system consider desirable? Calorie density, fat, starch, sugar, salt, free glutamate (umami), certain textures (easily chewed, soft or crunchy, solid fat), certain flavors, an absence of bitterness, food variety, and drugs such as alcohol and caffeine. Our brains are highly attuned to these qualities because they’re all elements of nutritious, calorie-dense foods that would have sustained our ancestors in a natural environment, but today, the exaggerated combinations of these qualities used by processed food manufacturers, chefs and sometimes even home cooks overstimulate our natural reward pathways (19). Commercial foods are professionally designed to maximize reward, because reward is precisely what keeps you coming back for more. Processed junk foods such as ice cream, fast food, sweetened soda, cookies, cake, candy, pizza and deep fried foods are all archetypal hyper-rewarding foods.

Palatability is a related concept—it’s determined in part by inborn preferences (e.g., a taste for sugar and energy dense foods), and in part by the reward system (acquired tastes). Palatability is governed by the hedonic system in the brain, which is closely integrated with the reward system. Imagine yourself sitting at the dinner table, stuffed after a large meal. Then the cake and ice cream appear, and suddenly you have enough room left for another 250 calories of food. Would you have eaten a large, unseasoned baked potato (250 calories) if someone had put one in front of you at that point? Foods that stimulate the hedonic system have a well known ability to increase food intake, and this effect can be replicated using drugs that activate these circuits directly (20).
The reward system is what motivates you to get food and put it to your lips, every time you eat. When scientists shut it down in mice, they stop seeking food, even though they’ll still eat if it’s put into their mouths (21). The hedonic system influences how much you eat once you begin a meal (22). Together, reward and hedonic circuitry in the brain determine in large part how often you seek food, what foods you select, and how much you eat at a sitting.
Other factors like the sedentary lifestyles of Americans are beyond the scope of the article, but what's there is scary enough. And here's exhibit A: Why Bother Chewing? Pepsi Out to 'Snackify' Beverages and 'Drinkify' Snacks (Treehugger):
Pepsi is rolling out a new product next month: Tropolis, a drinkable snack. It's marketing its Tropolis "smooth blend of real squeezable fruit" to moms and kids, apparently to replace the role of actual fruit. Why is this not the greatest idea ever? Fruits' optimal nutrients come when they are eaten whole: you get all the fiber and vitamins in one easy (naturally compostable) package, instead of what Marion Nestle called straight sugar in these fruit concentrate drinks...The Journal paraphrases Mehmood Khan, an endocrinologist who heads Pepsi's nutrition group: it's outdated to think that snacks are dry and beverages are wet. Tropolis will be launched in test markets in the Midwest next month, at 80 calories a pop and in apple, grape and cherry flavors.
It's no surprise, PepsiCo is the largest food company in America, and it makes money by selling more product, whatever the consequences, much like a drug pusher. This article gives a good overview of some of their nefarious corporate practices:
You may just think soft drinks when you hear the name, but PepsiCo actually owns a dizzying array of food and beverage brands across five massive divisions: Pepsi-Cola, Frito-Lay, Gatorade, Tropicana, and Quaker Oats. As I recently told CNBC for their documentary, Pepsi’s Challenge, perhaps the leading maker of sugary drinks and salty snacks should bear some responsibility for America’s bad eating habits.

To examine the company further, I ask in a lengthy article just published online in the City University of New York Law Review, “PepsiCo and Public Health: Is the Nation’s Largest Food Company a Model of Corporate Responsibility or Master of Public Relations?”

The article describes how PepsiCo utilizes an array of public relations maneuvers to convince Americans to keep buying its products, despite copious health advice to the contrary. Moreover, PepsiCo engages in lobbying and other underhanded behavior that defy its self-proclaimed “Performance with Purpose” image. These tactics include:
  • Describing questionable products such as baked chips and diet soda as “better for you” while attempting to engineer healthier junk food with such novelties as “drinkable oats.”
  • Exploiting an increasing desire for local food with “farmwashing” ad campaigns for potato chips.
  • Hiring respected public health experts and medical doctors to represent the company, creating an illusion of having a health-oriented mission, instead of being driven by profit.
  • Continuing to market its unhealthy products to children, despite numerous promises to the contrary, and lobbying to undermine federal policy aimed at reducing junk food marketing to kids.
  • Inserting its self-serving public relations message into a respected annual scientific report funded by top health foundations.
  • Buying off nonprofits by engaging in a host of philanthropic efforts such as its ubiquitous Pepsi Refresh program, all the name of moving more products.
  • Aggressively marching into the developing world to ensure continued growth globally as western markets become saturated with salt, sugar, and fat.
Throughout the article, I show how PepsiCo uses deliberately vague language in its annual report and other documents in which the company claims to be a responsible corporate citizen, thereby making evaluating such claims impossible. We cannot trust PepsiCo or any other food company to “do the right thing” when it comes to fixing the mess they got us into in the first place.
Is PepsiCo The Master of Corporate Spin? (Treehugger)

Even Economists are starting to take notice: Rogoff: Coronary Capitalism (Economist's View). covers both Rogoff's article and one about regulating sugar.

Here's a chart that really drives home the problem:

So what's the advice?

Diet trials have shown that a ‘simple’ diet, low in palatability and reward value, reduces hunger and causes fat loss in obese humans and animals, apparently by lowering the ‘defended’ level of fat mass (30, 31, 32, 33). This may be a reason why virtually any diet in which food choices are restricted (e.g., Paleo, vegan, fruitarian), including diametrically opposed approaches like low-fat and low-carbohydrate diets, can reduce food intake and body fatness in clinical trials. As stated by Nora Volkow, director of the National Institute on Drug Abuse, “The common denominator of such diets is that neither allows consumption of the very caloric and seductive foods that combine high fat with high carbohydrates” (34). Hyper-rewarding/palatable foods—candy, chocolate, ice cream, chips, cookies, cakes, fast food, sweetened beverages and pizza—are uniquely fattening and should be the first foods to go in any fat loss attempt. Some people will benefit from further simplifying the diet.
So get on a diet...any diet, it doesn't matter which. Eat To Live, Raw, Caveman, pick one. Don't eat foods your grandfather didn't eat. Grow your own vegetables and herbs, and buy from reputable small producers.

And see (via Of Two Minds):

The Physics Diet

The Physics of Gluttony

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