The guidelines also establish ranges (called acceptable macronutrient distribution ranges or AMDR) for fat, carbohydrates and protein, instead of exact percentages of calories or numbers of grams. The report maintains that since all three categories serve as sources of energy, they can, to some extent, substitute for one another in providing calories.
Not everyone who is underweight suffers from an eating disorder, but anorexia and bulimia are serious health problems in this country; an estimated 500,000 women suffer from anorexia, and 1 to 2 million women struggle with bulimia. Women with anorexia nervosa starve themselves and/or exercise excessively, losing anywhere from 15 percent to 60 percent of their normal body weight. Some die. Women with bulimia nervosa binge on large quantities of food—up to 20,000 calories at one time—and then try to get rid of the excess calories. Some purge by inducing vomiting, abusing laxatives and diuretics or by taking enemas. Others fast or exercise to extremes.
Changes in the way research ethics was visualised in the wake of the Nuremberg Trials (1946), led to an atmosphere of protectionism of groups deemed to be vulnerable that was often legislated or regulated. This resulted in the relative underrepresentation of women in clinical trials. The position of women in research was further compromised in 1977, when in response to the tragedies resulting from thalidomide and diethylstilbestrol (DES), the United States Food and Drug Administration (FDA) prohibited women of child-bearing years from participation in early stage clinical trials. In practice this ban was often applied very widely to exclude all women. Women, at least those in the child-bearing years, were also deemed unsuitable research subjects due to their fluctuating hormonal levels during the menstrual cycle. However, research has demonstrated significant biological differences between the sexes in rates of susceptibility, symptoms and response to treatment in many major areas of health, including heart disease and some cancers. These exclusions pose a threat to the application of evidence-based medicine to women, and compromise to care offered to both women and men.