Callaway C W
Center for Clinical Nutrition, George Washington University Medical Center, Washington, DC.
Public Health Rep. 1987 Jul-Aug;102(4 Suppl):26-9.
Obesity is not a single disease, but a variety of conditions resulting from different mechanisms and associated with various types and degrees of risks. To determine who should lose weight, how much weight should be lost, and how to undertake weight loss, the following types of information are needed: personal-demographic data, developmental patterns, family history, energy balance, body composition/fat distribution, psychological/behavioral measures, endocrine/metabolic measures, complications and associated conditions. Weight reduction should be undertaken by women with morbid obesity, with complications secondary to the obesity, with a strong family history of conditions associated with obesity, or with increased abdomen:hip ratios. In contrast, women who have excess weight localized in the hips and thighs and no personal or family history of associated conditions may not benefit from dietary restriction. Low calorie diets result in adaptive changes, "designed" to prolong survival in the face of famine. These include changes in water balance, metabolic rate, and appetite. Metabolic rate declines, allowing the individual to burn fewer and fewer calories. Each time a woman diets she tends to lose weight less rapidly than the time before. "Restrained eating" predisposes binge eating. Indeed, bulimia rarely occurs in the absence of prior caloric restrictions. Current medical definitions of obesity do not consider these nuances. Existing definitions "over-diagnose" obesity in women, in general, and in older women and nonwhite women, in particular. For example, by existing standards, more than 60 percent of black women more than 45 years of age are considered obese. In contrast, the health risks of similar degrees of obesity are substantially greater for men than for women. Part of the problems lies in the fact that many women have pear-shaped fat distribution,a pattern which is not associated with increased health risks.Current cultural definitions of obesity for women distort the picture even further. In the past 20 years,there has been a progressive decline in the weight-for height of such "culture models" as Playboy centerfold subjects and Miss America contestants. Attempting to achieve such low weights predisposes women to an endless cycle of dieting and regaining, and contributes to the growing problems of eating disorders, including anorexia nervosa and bulimia.
肥胖并非单一疾病，而是由不同机制导致的多种状况，且与各类不同程度的风险相关。为确定谁应该减肥、减多少体重以及如何进行减肥，需要以下几类信息：个人人口统计学数据、发育模式、家族病史、能量平衡、身体成分/脂肪分布、心理/行为指标、内分泌/代谢指标、并发症及相关状况。患有病态肥胖、肥胖继发并发症、有与肥胖相关疾病的强烈家族病史或腰臀比增加的女性应该进行减肥。相比之下，臀部和大腿部位脂肪过多且无个人或家族相关病史的女性可能无法从饮食限制中获益。低热量饮食会导致适应性变化，这些变化“旨在”在面临饥荒时延长生存时间。这些变化包括水平衡、代谢率和食欲的改变。代谢率下降，使得个体消耗的热量越来越少。每次女性节食时，体重减轻的速度往往比上一次更慢。“节制饮食”易引发暴饮暴食。事实上，若没有先前的热量限制，很少会发生贪食症。当前对肥胖的医学定义并未考虑到这些细微差别。总体而言，现有定义“过度诊断”了女性的肥胖问题，尤其是老年女性和非白人女性。例如，按照现有标准，超过60%的45岁以上黑人女性被认为肥胖。相比之下，相同程度肥胖对男性的健康风险比对女性大得多。部分问题在于，许多女性的脂肪分布呈梨形，这种模式与健康风险增加无关。当前对女性肥胖的文化定义更是歪曲了实际情况。在过去20年里，《花花公子》杂志插页模特和美国小姐参赛者等“文化模特”的身高体重比一直在逐渐下降。试图达到如此低的体重会使女性陷入节食和体重反弹的无尽循环，并加剧饮食失调问题（包括神经性厌食症和贪食症）的不断增加。
