Due: Wednesday (11/2/16) or Thursday (11/3/16) in class
Issue Overview: What to Eat
Alan Bjerga, Bloomberg
In twice-a-decade dietary guidelines issued in early 2016, the U.S. government made two notable reversals, dropping its previous advice to restrict dietary cholesterol and total fat consumption. The panel of scientists that drafted the guidelines wrote that a healthy diet is “lower in red and processed meat,” which have been associated with elevated death rates from cancer and heart disease. After strong objections from the meat industry, that caution was dropped. In the final document, men and teenage boys were advised to eat less protein by decreasing consumption of meat, poultry and eggs.
High levels of cholesterol in blood have long been linked to heart disease. But the body produces the substance on its own, and researchers increasingly have concluded that in healthy people, consuming cholesterol-laden foods like eggs and shellfish doesn’t affect blood levels very much. Guidance on fats has changed as nutritionists have begun to distinguish among what they think are really bad trans fats (in margarine and vegetable shortening), bad saturated fats (in red meat and whole milk) and good unsaturated fats (in olive oil and nuts). The new U.S. guidelines recommend eschewing trans fats and limiting saturated fats to 10 percent of a day’s calories. Fat science is far from settled, however. A 2013 review of 72 studies found no significant association between saturated fat and heart disease. This disconnect underscores a weakness in nutrition science. It relies not so much on controlled experiments but on observational studies, in which researchers collect data on a group of people and try to connect something about them with a certain outcome. Because so many other factors can affect the outcome, such studies have a limited ability to determine causality. Their results often cannot be replicated. Also, nutrition studies rely on volunteers to self-report what they ate, producing unreliable data.
Critics of the complicated U.S. guidelines — the 2016 edition is 204 pages long — argue that they have at times contributed to worsening health. For instance, warnings that the fat in butter and cream produced heart attacks prompted many consumers to switch to margarine and nondairy creamer, which contain the trans fat scientists now think is more hazardous. Admonitions to avoid fat altogether led Americans to eat significantly more carbohydrates — many promoted as “fat-free” — which helped drive the country’s current obesity and type 2 diabetes epidemics. The 2016 guidelines won praise for focusing less on individual nutrients than on dietary patterns, better reflecting how people actually eat and accounting for the fact that foods interact with each other. Still, detractors note that while the text mentions specific foods that are recommended (a variety of vegetables, whole fruits, grains), when it comes to things to avoid, it reverts to referencing nutrients (added sugars, saturated fats, sodium) rather than items that contain these things (soda, meat and junk food). The critics blame intense lobbying by the food industry. Government officials have said the guidelines are based on a rigorous review of current nutrition science and consideration of comments from the public and input from federal agencies. To make its recommendations more useful and credible, some nutritionists think the U.S. should simplify them to the basics (from great-grandmother’s time, perhaps), which would put them more in line with the eating advice given by the World Health Organization.
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1. Which of the following accurately represents the relationship between the article’s ideas?
A) Nutritional guidelines and advice in the U.S. have been extremely inconsistent; therefore, some nutritionists think that people should listen to their grandmothers' advice.
B) Nutritional guidelines and advice in the U.S. have been extremely inconsistent; this is because of unreliable nutrition science and lobbying by the food industry.
C) The science behind what to eat can be very confusing; this is because of observational studies that rely on volunteers who may not tell the truth about what they eat.
D) The science behind what to eat can be very confusing; therefore, people should try to avoid fats found in margarine and eat more fats in foods like olives and nuts.
2. Which of the following sentences from the article BEST supports the central idea that conflicting and confusing guidelines have been harmful to people's health?
A) The panel of scientists that drafted the guidelines wrote that a healthy diet is “lower in red and processed meat,” which have been associated with elevated death rates from cancer and heart disease.
B) But the body produces the substance on its own, and researchers increasingly have concluded that in healthy people, consuming cholesterol-laden foods such as eggs and shellfish doesn’t affect blood levels very much.
C) Admonitions to avoid fat altogether led Americans to eat significantly more carbohydrates — many promoted as “fat-free” — which helped drive the country’s current obesity and type 2 diabetes epidemics.
D) Government officials have said the guidelines are based on a rigorous review of current nutrition science and consideration of comments from the public and input from federal agencies.
3. Read the following sentences from the article:
“In a 2012 U.S. poll, half of those surveyed said it was easier to do their taxes than to figure out how to eat healthily. Why isn’t it simpler? For one thing, nutrition science is relatively young and inherently unreliable. For another, there’s lots of money at stake, leading businesses to argue that what they offer is good for consumers, even if it isn’t.”
Based on the text AND the information in the chart, which of the following predictions is MOST reasonable?A) Other countries will begin to agree on what foods are best to eat.
B) The U.S. will soon have clear guidelines about what to eat.
C) People will soon stop listening to what the guidelines say.
D) Nutritional recommendations will continue to be inconsistent.
4. The chart shows that there are conflicting pieces of advice about how much milk and meat to eat. Based on the article, what is the explanation for this difference?
A) Americans have been told to avoid fat altogether and eat pasta instead.
B) Some cultures have a preference for the taste of milk and meat and some like other foods.
C) There are weaknesses in nutrition science about what kinds of fats are healthy.
D) The U.S. meat and milk industries want people to consume more of their products.
Provide a scientific summary of the article by identifying the article's claim. Also, provide three (3) pieces of evidence from the article which support this claim. Then provide a reasoning which links all three pieces of evidence to support the article’s claim.