Misunderstandings and Deceptive
Statements
Some individuals may be confused or misled about important
dietary issues based on the following inaccurate claims:
1. “High-protein diets cause dramatic weight loss.”
The weight loss typically occurring with high-protein
diets—approximately 11-16 pounds over the course
of a year5,6—is not significantly different from
that seen with other weight-reduction regimens or with
low-fat, vegetarian eating patterns.
2. “Fatty foods must not be fattening, because
fat intake fell during the 1980s, just as America's
obesity epidemic began.”
Some news stories have encouraged the public to discount
health warnings about the amount of fat (especially
saturated fat) in the diet, suggesting that fat intake
declined during the 1980s, an era during which obesity
became more common. However, food surveys from the National
Center for Health Statistics from 1980 to 1991 show
that daily per capita fat intake did not drop during
that period. For adults, fat intake averaged 81 grams
in 1980 and was essentially unchanged in 1991.
While the American public added sodas and other non-fat
foods to the diet, forcing the percentage of calories
from fat to decline slightly, the actual amount of fat
in the American diet did not drop at all. What did change
was portion size. A report in the Journal of the American
Medical Association confirmed that meal sizes have steadily
risen over recent decades.28
A notable contributor to fat and calorie intake in recent
years is cheese consumption. Per capita cheese consumption
rose from 15 pounds in 1975 to more than 30 pounds in
1999. Typical cheeses derive approximately 70 percent
of energy from fat and are a significant source of dietary
cholesterol.
3. “Fat and cholesterol have nothing to do with
heart problems.”
Abundant scientific evidence establishes that dietary
fat and cholesterol are associated with increased cardiovascular
disease risk.16 Nonetheless, some popular-press articles
have incorrectly suggested that evidence supporting
this relationship is weak and inconsistent.
In addition, the late diet-book author Robert Atkins
claimed in interviews that, despite his having followed
a fatty, high-cholesterol diet for decades, he did not
have artery blockages. The net result may be that dieters
believe they can safely disregard well-established contributors
to heart disease. After Dr. Atkins’ death, his
widow and his personal physician revealed that Dr. Atkins
had indeed had coronary artery blockages, although they
have maintained that these blockages had nothing to
do with his death.
4. “Meat doesn't boost insulin; only carbohydrates
do that, and that's why they make people fat.”
Popular books and news stories have encouraged individuals
to avoid carbohydrate-rich foods, suggesting that high-protein
foods will not stimulate insulin release. However, contrary
to this popular myth, proteins stimulate insulin release,
just as carbohydrates do. Clinical studies indicate
that beef and cheese cause a bigger insulin release
than pasta, and fish produces a bigger insulin release
than popcorn.15
Also, it is important to realize that different carbohydrate-rich
foods have very different effects. Most cause a gradual,
temporary, and safe rise in blood sugar after meals.
Beans, green leafy vegetables, and most fruits are in
this healthful category. The main exceptions are large
baking potatoes, white bread, and sugary foods, which
can cause an overly rapid rise in blood sugar.
5. “People who eat the most carbohydrates tend
to gain the most weight.”
Popular diet books point out that cutting out carbohydrate-containing
foods may lead to temporary weight loss. This fact has
been misinterpreted as suggesting that carbohydrate-rich
foods are the cause of obesity. In epidemiological studies
and clinical trials, the reverse has been shown to be
true. Many people throughout Asia consume large amounts
of carbohydrate in the form of rice, noodles, and vegetables
and generally have lower body weights than Americans—including
Asian Americans—who eat large amounts of meat,
dairy products, and fried foods. Similarly, vegetarians,
who generally follow diets rich in carbohydrates, typically
have significantly lower body weights than omnivores.
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