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Objective Dietary supplements are not recommended as part of a weight-loss program due to concerns about efficacy and safety. This study sought to assess prevalence and duration of nonprescription weight-loss supplement use, associated weight-control behaviors, discussion of use with a health care professional, and specific ingredient use. Participants and design Adults aged [greater than or equal to] 18 years (n=9,403) completed a cross-sectional population-based telephone survey of health behaviors from September 2002 through December 2002. Statistical analyses performed Both [chi square] and t tests were conducted for categorical and mean comparisons and multiple variable logistic regression was used to determine significant predictors. Results An estimated 15.2% of adults (women 20.6%, men 9.7%) had ever used a weight-loss supplement and 8.7% had past year use (women 11.3%, men 6.0%); highest use was among women aged 18 to 34 years (16.7%). In regression models, use was equally prevalent among race/ethnic groups and education levels. One in 10 (10.2%) of users reported [greater than or equal to] 12 month use, with less frequent long-term use in women (7.7%) than men (15.0%), P=0.01. Almost one third (30.2%) of users discussed use during the past year; 73.8% used a supplement containing a stimulant including ephedra, caffeine, and/or bitter orange. Conclusions Use of supplements for losing weight seems to be common among many segments of the US adult population. Many adults are long-term users and most do not discuss this practice with their physician. Most of the weight-loss supplements taken contain stimulants. Qualified professionals should inquire about use of supplements for weight loss to facilitate discussion about the lack of efficacy data, possible adverse effects, as well as to dispel misinformation that may interfere with sound weight-management practices.

Objective This study investigated food choices made by individuals consuming diets differing in energy density and explores relationships between energy density and diet quality. Design Cross-sectional, nationally representative survey. Subjects 7,500 adults (older than 19 years) in the 1994-1996 Continuing Survey of Food Intakes by Individuals. Statistical analysis Energy density values were calculated from reported food intake. Subjects were classified as consuming a low-energy-density diet, medium-energy-density diet, or high-energy-density diet using tertile cutoffs. For each group, the percentage consuming various foods/beverages and the mean amount of foods/beverages they consumed was determined along with mean nutrient intakes. Results Compared with participants consuming a high-energy-density diet, those with a low-energy-density diet had a lower energy intake but consumed more food, by weight, from most food groups. A low-energy-density diet included a relatively high proportion of foods high in micronutrients and water and low in fat, such as fruits and vegetables. Subjects with a low-energy-density diet consumed fewer (nonwater) beverages such as caloric carbonated beverages. They also consumed less fat and had higher intakes of several important micronutrients, including vitamins A, C, and B-6, folate, iron, calcium, and potassium. Conclusions These analyses further demonstrate the beneficial effects of a low-energy-density diet, which was associated with lower energy intakes, higher food intakes, and higher diet quality than a high-energy-density diet. To achieve a low-energy-density diet, individuals should be encouraged to eat a variety of fruits and vegetables as well as low-fat/reduced-fat, nutrient-dense, and/or water-rich grains, dairy products, and meats/meat alternatives.

The food system is a widely used concept, but few systematic frameworks model the full scope and structure of the food and nutrition system. Bibliographic searches, a modified Delphi technique, focus groups and interviews with experts on the topic were conducted to identify existing models of agriculture, food, nutrition, health and environmental systems. These models were examined, classified and synthesized into an integrated conceptual model of the food and nutrition system. Few existing models broadly described the system and most focused on one disciplinary perspective or one segment of the system. Four major types of models were identified: food chains, food cycles, food webs and food contexts. The integrated model developed here included three subsystems (producer, consumer, nutrition) and nine stages (production, processing, distribution, acquisition, preparation, consumption, digestion, transport, metabolism). The integrated model considers the processes and transformations that occur within the system and relationships between the system and other systems in the biophysical and social environments. The integrated conceptual model of the food and nutrition system presents food and nutrition activities as part of a larger context and identifies linkages among the many disciplines that deal with the food and nutrition system. Key words - model, food, nutrition, health, agriculture, diet, systems

ABSTRACT This study evaluated the validity and reliability of a modified qualitative dietary fat index questionnaire (QFQ) in an adolescent minority population. The QFQ was administered to study participants twice [...]

ABSTRACT There is essentially no ideal method of dietary assessment. Physiologic methods (ie, doubly labeled water) probably come closest, but high cost, participant burden, and limited information limit their use. [...]

Traditional methods for assessing dietary behavior such as 24-hour dietary recalls, diet records, and food frequency questionnaires may not measure what we want to know about dietary behaviors of a [...]