food-pics example method section

excerpts from: 
Meule, A., Kuebler, A., & Blechert, J. (2013). Time course of electrocortical food-cue responses during cognitive regulation of craving. Frontiers in Eating Behavior, 4, 1-11. Article

"Stimuli were selected from a food picture database featuring food images with simple figure ground compositions for experimental research (Meule and Blechert, 2012) and comprised pictures of 34 high-calorie and 34 low-calorie foods. High-calorie food pictures included both sweet (e.g. candy, chocolate, cake) and savory (e.g. French fries, burger, pizza) foods (Fig. 1a). Low-calorie food pictures included vegetables, fruits, salad, and crisp bread (Fig. 1b). All pictures had the same resolution and color depth (600 x 450 pixels, 96 dpi, 24 bpp) and were homogenous with regard to background color and camera distance. High- and low-calorie food pictures did not differ in color (RGB), brightness, spatial frequencies and contrast (all ts(66) < 0.78, ns), visual complexity ( edge detection: t(66) = -0.95, ns; subjective complexity ratings: t(66) = -1.41, ns), and subjective palatability ratings (t(66) = 1.36, ns). High-calorie food pictures displayed foods with a higher calorie density (M = 360.98 kcal/100g, SD = 140.87) as compared with low-calorie food pictures (M = 35.44 kcal/100g, SD = 26.66; t(66) = 13.24, p < .001). Similarly, the total amount of calories displayed in high-calorie food pictures (M = 625.23 kcal/image, SD = 680.92) was higher than that of low-calorie food pictures (M = 97.95 kcal/image, SD = 109.81, t(66) = 4.56, p < .001)."