Differential dietary habits among 570 young underweight Japanese women with and without a desire for thinness: a comparison with normal weight counterparts.

The strong social pressure for thinness in Japanese society has produced a dramatic increase in underweight (body mass index: <18.5 kg/m2) among young women. Being underweight is associated with several negative health outcomes, including nutritional deficiency, osteoporosis, and unfavourable pregnancy outcomes. However, evidence which would help deal with this problem from a public health perspective is scarce. Here, we aimed to identify the dietary characteristics of underweight female university students, particularly those with a desire for thinness. Data on dietary habits and other lifestyle variables, including the desire for thinness, were obtained through a self-administered questionnaire survey conducted at 54 academic institutions in Japan, from which we selected 3634 female students for analysis. The subjects were divided into three groups of normal weight (84.3%), and underweight with (6.4%) or without (9.3%) a desire for thinness. After adjusting for potential confounders, the underweight subjects with a desire for thinness consumed less cereal and rice, whereas those without a desire for thinness consumed more cereal and rice than the normal weight subjects. In addition, those without a desire for thinness consumed less confectionaries, including candies and ice cream, and less fats and oils than the normal weight subjects. These results suggest that dietary habits differ between underweight women with and without a desire for thinness. Although both groups require nutritional education to maintain appropriate body weight, underweight women with a desire for thinness require particular attention to improve recognition of their constitution and dietary habits.