Adele H. Hite

In the face of contradictory evidence: Report of the Dietary Guidelines for Americans Committee

Concerns that were raised with the first dietary recommendations 30 y ago have yet to be adequately addressed. The initial Dietary Goals for Americans (1977) proposed increases in carbohydrate intake and decreases in fat, saturated fat, cholesterol, and salt consumption that are carried further in the 2010 Dietary Guidelines Advisory Committee (DGAC) Report. Important aspects of these recommendations remain unproven, yet a dietary shift in this direction has already taken place even as overweight/obesity and diabetes have increased. Although appealing to an evidence-based methodology, the DGAC Report demonstrates several critical weaknesses, including use of an incomplete body of relevant science; inaccurately representing, interpreting, or summarizing the literature; and drawing conclusions and/or making recommendations that do not reflect the limitations or controversies in the science. An objective assessment of evidence in the DGAC Report does not suggest a conclusive proscription against low-carbohydrate diets. The DGAC Report does not provide sufficient evidence to conclude that increases in whole grain and fiber and decreases in dietary saturated fat, salt, and animal protein will lead to positive health outcomes. Lack of supporting evidence limits the value of the proposed recommendations as guidance for consumers or as the basis for public health policy. It is time to reexamine how US dietary guidelines are created and ask whether the current process is still appropriate for our needs.

Low-Carbohydrate Diet Review Shifting the Paradigm

What does a clinician need to know about low-carbohydrate (LC) diets? This review examines and compares the safety and the effectiveness of a LC approach as an alternative to a low-fat (LF), high-carbohydrate diet, the current standard for weight loss and/or chronic disease prevention. In short-term and long-term comparison studies, ad libitum and isocaloric therapeutic diets with varying degrees of carbohydrate restriction perform as well as or better than comparable LF diets with regard to weight loss, lipid levels, glucose and insulin response, blood pressure, and other important cardiovascular risk markers in both normal subjects and those with metabolic and other health-related disorders. The metabolic, hormonal, and appetite signaling effects of carbohydrate reduction suggest an underlying scientific basis for considering it as an alternative approach to LF, high-carbohydrate recommendations in addressing overweight/obesity and chronic disease in America. It is time to embrace LC diets as a viable option to aid in reversing diabetes mellitus, risk factors for heart disease, and the epidemic of obesity.

Statistical review of US macronutrient consumption data, 1965–2011: Americans have been following dietary guidelines, coincident with the rise in obesity

BACKGROUND For almost 50 y, the US National Health and Nutrition Examination Survey (NHANES) has measured the caloric consumption, and body heights and weights of Americans. The aim of this study was to determine, based on that data, how macronutrient consumption patterns and the weight and body mass index in the US adult population have evolved since the 1960s. METHODS We conducted the first comprehensive analysis of the NHANES data, documenting how macronutrient consumption patterns and the weight and body mass index in the US adult population have evolved since the 1960s. RESULTS Americans in general have been following the nutrition advice that the American Heart Association and the US Departments of Agriculture and Health and Human Services have been issuing for more than 40 y: Consumption of fats has dropped from 45% to 34% with a corresponding increase in carbohydrate consumption from 39% to 51% of total caloric intake. In addition, from 1971 to 2011, average weight and body mass index have increased dramatically, with the percentage of overweight or obese Americans increasing from 42% in 1971 to 66% in 2011. CONCLUSIONS Since 1971, the shift in macronutrient share from fat to carbohydrate is primarily due to an increase in absolute consumption of carbohydrate as opposed to a change in total fat consumption. General adherence to recommendations to reduce fat consumption has coincided with a substantial increase in obesity.

Arsenic and rice: A call for regulation

The US Food and Drug Administration (FDA) has been monitoring the arsenic content in foods since 1991 in order to estimate how much arsenic Americans are consuming [1]. Despite 20 years of data collection and well-established science describing the health risks associated with arsenic exposure, no standards have been set limiting the amount of arsenic allowable in foods [2]. Total arsenic content in food can come from organic and inorganic forms. Although total arsenic has been more thoroughly quantified than subtypes of arsenic, it is the inorganic form that poses the greatest health risks to humans. Studies have demonstrated that long-term exposure to inorganic arsenic in drinking water may result in increased risk of skin, bladder, lung, kidney, liver, and prostate cancer and is also associated with alterations in gastrointestinal, cardiovascular, hematological, pulmonary, neurological, immunological, and reproductive/developmental function [3]. Fetal exposure to inorganic arsenic is associated in both population and laboratory studies with an increased risk of adverse health effects later in life [4]. Arsenic occurs naturally in soil in many geographic areas; it can also result from man-made contamination from industrial pollution and pesticide use. Humans may be exposed to risk through both the food and water supply. Arsenic exposure through contaminated drinking water has been welldocumented, resulting in the creation of US, EU, and World Health Organization safe drinking water standards [2]. For those populations not exposed to drinking water with elevated arsenic levels, rice consumption is by far the largest dietary source of inorganic arsenic [5]. The anaerobic growing conditions of flooded rice paddies and the unique physiology of the rice plant allow rice to take up arsenic from the environment in an efficient manner and sequester it within the plant, including in the rice grain; arsenic may accumulate in the rice plant at much greater concentrations than in the soil [5]. Rice consumption has been related to urinary arsenic concentrations in both adults and children [6]. Although rice consumption in America and most European countries is well below the global average, consumption has been steadily increasing for decades. Rice consumption has doubled in America since the 1980s, with the increase attributed in part to the influx of immigrants from Asia, Latin America, and Africa, whose food culture relies heavily on this staple grain [7]. However, rice consumption is not limited to these groups. Consumption of rice in the form of processed foods has increased

Destined for greater obesity

Fig. 1. The rise in obesity in America began in the early 1980s after the release of the first Dietary Guidelines for Americans [16]. Arewe destined to become an even fatter nation? The Dietary Guidelines are meant to answer a simple question: What should Americans eat to stay healthy? [1]. Since the first official Dietary Guidelines were released in 1980, their purpose focused on both nutrient adequacy and “the impact of diet on chronic disease” [2]. The unwavering mantra continues: reduce consumption of fat, saturated fat, cholesterol, added sugars, and sodium; increase consumption of grain and cereal products, vegetables, and fruits. In 1977, frustrated with the Department of (then) Health, Education, and Welfare’s neglect of the link between diet and disease, Senator McGovern pushed to have the US Department of Agriculture (USDA) take the lead in nutritional research and education [3]. That same year, the Senate Select Committee on Nutrition and Human Needs under his leadership released the Dietary Goals for Americans [4]. Written by political staffers after considering testimony from nutritionists, these Goals attributed America’s “epidemic of killer diseases”dobesity, diabetes, heart disease, and cancerdto an increase in “fatty and cholesterolrich foods” [5] and advocated Americans reduce dietary fat and increase grain and cereal consumption, a very controversial recommendation in the absence of sufficient supporting data [6] and contrary data suggesting increased dietary carbohydrate results in increased blood triglycerides associated with type 2 diabetes and heart disease [7,8]. The controversy fell on essentially deaf ears; few changes were made and the 1977 Goals became the first Dietary Guidelines for Americans in 1980, written jointly by USDA and HEW with little input from the nutritional scientific community [9]. Three months later, the Food and Nutrition Board of the National Academy of Sciences released a report stating there was no clear evidence that restricting dietary fat or cholesterol would result in health benefits for the average person and that good health could be achieved simply by maintaining a healthy weight [10]. Later that year, the conflicting viewpoints led the Senate Agriculture Appropriations Committee to establish an expert committee to evaluate the available scientific data and recommend possible changes to the 1980 Dietary Guidelines [10]. Consequently, the USDA created a specific departmental agency to house and manage nutritional issues. The Dietary Guidelines were thus institutionalized, becoming the Federal document that shapes all government dietary guidance, creates nationwide nutrition standards, influences agricultural policies, and directs how food manufacturers target consumer demand. The primary assumptions inherent in the Dietary Guidelines linking them to specific health outcomes have never been tested

Nutritional Epidemiology of Chronic Disease and Defining “Healthy Diet”

ABSTRACT This investigation follows the shift in US “healthy diet” guidance from prevention of nutritional deficiencies to prevention of chronic diseases. In particular, it shows how the Dietary Goals for Americans, first published in 1977, came to be based on the relatively new science of nutritional epidemiology of chronic disease, a methodology of statistical analysis whose most influential datasets relied primarily on white health professionals deeply invested in cultural norms surrounding dietary health. With this scientific authority, health differences among subpopulations came to be blamed on a lack of agency at best, if not poor judgment and personal failure.