BACKGROUND: Poor quality irrigation water is a major cause of disease transmission for urban inhabitants consuming fresh produce in many developing countries. Irradiation of food is an alternative approach to reducing health risks for consumers, but its implementation depends heavily on consumer acceptance.RESULTS: In this pilot study, we show that most respondents consider the water quality of Mexico City to be poor and a health risk, and would be willing to pay for irradiated food as a means of pasteurizing fresh iceberg lettuce.CONCLUSION: Irradiated food could, potentially, be accepted in developing countries that have problems with water quality. Such acceptance would presumably be due to the perception that such a novel technology would (1) alleviate water impairment, and (2) lead to economic improvement. It is then possible that the public considers that water quality is a more pressing concern than any potential side effects of food irradiation.

Objective: We assessed the extent of energy misreporting from the use of a self-administered 7-day diet record (7-DDR) and a widely used food frequency questionnaire (FFQ) compared to total energy expenditure from doubly labeled water (DLW) in a group of postmenopausal women. Design: At baseline, 65 healthy postmenopausal women were instructed to fill out the National Cancer Institute's (NCI) FFQ and a 7-DDR. Average total energy expenditure using the DLW method was also performed at baseline. Results: On average, the women underestimated total energy intake compared to total energy expenditure assessed from DLW by 37% on the 7-DDR and 42% on the FFQ. Conclusions: These findings suggest that the interpretation of findings from the 7-DDR- and FFQ-based energy-disease association studies in postmenopausal women needs further evaluation. Sponsorship: This research was supported (in part) by the Intramural Program of the NIH (National Cancer Institute).

Objective: To study whether eating or physical-activity (PA) habits differ between obese and non-obese monozygotic (MZ) co-twins independent of genetic effects. Methods: Rare MZ pairs discordant for obesity (n=14, body mass index difference 5.2±1.8 kg m–2) and weight-concordant control pairs (n=10, 1.0±0.7 kg m–2), identified through a population-based registry of 24–28-year-old twins (n=658 MZ pairs), completed 3-day food and PA diaries and eating behavior questionnaires. Each twin was asked to compare his/her own eating and PA patterns with the co-twin's behavior by structured questionnaires. Accuracy of energy intake was validated by doubly labeled water. Results: Non-obese co-twins consistently reported that their obese twin siblings ate more food overall, consumed less healthy foods and exercised less than the non-obese co-twins do. However, no differences in energy intake (9.6±1.0 MJ per day vs 9.8±1.1 MJ per day, respectively) in the food diaries or in the mean PA level (1.74±0.02 vs 1.79±0.04, respectively) in the PA diaries were found between obese and non-obese co-twins. A considerable underreporting of energy intake (3.2±1.1 MJ per day, P=0.036) and overreporting of PA (1.8±0.8 MJ per day, P=0.049) was observed in the obese, but not in the non-obese co-twins. Conclusions: On the basis of rare MZ twin pairs discordant for obesity, the co-twin assessments confirmed substantial differences in eating and PA behavior between obese and non-obese persons. These may be overlooked in population studies using food and PA diaries because of considerable misreporting by the obese.