Study On the Validity Of Instant Photography Method For Dietary Assessment In Undergraduate College Students

Abstract

Background A healthy diet in a college student life is critical to ensure their normal growth, study and development. Aim In order to accurately assess the dietary pattern of college students and guide it, our study aims to evaluate the validity of instant photography as an alternative dietary assessment method in college students. Methods Nine participants were enrolled and given a presentation on dietary assessment methods, including weighing, 24-hour recall, and instant photography. The participants took pictures of their foods from three angles before and after eating for constant seven days, foods weighing was completed by others. Then, the participants recalled the foods’ weights after 24 hours. Two trained observers estimated food weight from the digital images (n = 285) gathered at the end of the study with the aid of Chinese food atlas reference. Results Instant photograph showed significant correlation with weighing method on food weights of grains, tubers, vegetables, fruits, meat and eggs (all P ? 0.01 ). 24-hour method had similar correlation with weighing method on food weights except fruits. Compared with 24-hour recall, instant photograph displayed underestimation on weights of grains, tubers, vegetables, and meat. However, instant photograph had more accurate estimations on weights of fruits and egg. Furthermore, compared with nutrients data from weighing method, both instant photography and 24-hour recall methods showed promising estimations on the amounts of energy, protein, fat, carbohydrate, vitamin A, vitamin C, vitamin E, calcium, iron and zinc (all P < 0.001 ). Compared with 24-hour recall, instant photograph displayed underestimation on the amounts of energy, protein, fat, carbohydrate, vitamin A, vitamin C, vitamin E, zinc. However, instant photograph had a more accurate estimation on calcium. Conclusion Instant photography is an easy and feasible dietary assessment method for college students, with valid estimations.