Factor loadings and α if item deleted for each item in primary model of skill domain (before deleting any items)

Items	Functional skills	Interactive skills	Advocacy	Critical analysis of information	Food label reading skills	Cronbach’s α if item deleted
30. I can manage my weight by exercising and controlling the amount of food I eat.b	0.155	0.454	0.059	0.107	0.327	0.823
31. When buying meat, I can recognize its freshness and quality by Checking the appearance.	0.470	0.084	0.138	0.130	0.183	0.797
32. If I have to eat fast Foods (due to lack of time or cooking facilities), I can choose the healthier one.	0.309	0.136	0.240	0.047	0.395	0.801
33. I can buy groceries as much as I need, so that they do not get spoiled or wasted.	0.231	0.125	0.093	0.089	0.500	0.803
34. If my income suddenly is decreased, I will be able manage my expenses so as to buy enough food to ensure my health.b	0.144	0.226	0.191	0.109	0.418	0.807a
35. I am familiar with the basic skills of cooking (e.g. sautéing, frying, stewing rice, using salt and spices, etc.)	0.815	0.021	0.041	0.007	0.015	0.786
36. I know how to preserve foods through using methods such as drying or freezing.	0.666	0.140	0.149	0.012	0.187	0.785
37. I can prepare tasty and healthy foods that me and my family like it.	0.800	0.139	0.092	0.010	0.047	0.779
38. I easily can use cooking equipment such as pressure cooker, stove, and oven.	0.706	0.021	0.044	0.000	0.199	0.788
39. If some ingredients of a recipe are not available, I can change the recipe according to available ingredients.	0.754	0.203	0.095	0.060	0.064	0.787
40. I can make yoghurt from milk.	0.509	0.081	0.082	0.092	0.070	0.804
41. Have you ever experienced planting vegetables (e.g. basil, parsley or tomatoes) in the garden or pots?	0.475	0.129	0.008	0.067	0.082	0.802
42. I can separate dry and wet food disposals.	0.326	0.109	0.188	0.083	0.183	0.806
43. I have collected the nutritional information useful to me from different sources.	0.214	0.644	0.139	0.071	0.118	0.306
44. I use the internet when I am searching information about diet and nutrition.	0.056	0.442	0.130	0.095	0.079	0.408
45. I have changed my food habits based on the information I have got about nutrition.	0.119	0.659	0.113	0.139	0.203	0.326
46. I usually follow TV or radio talk shows on nutrition.	0.127	0.490	0.150	0.217	0.091	0.397
47. I follow information on characteristics of a balanced diet.	0.147	0.655	0.122	0.239	0.106	0.348
48. I can ask dietary experts (e.g., doctors, nurses, etc.) questions about healthy eating.b	-0.174	-0.560	0.122	0.059	0.001	0.646
49. When I am looking for information about nutrition, I don’t know which section in the health centers I can go to for help.b	0.083	-0.242	0.058	0.004	0.391	0.546
50. I discuss my thoughts about diet with others (including family, friends, and doctors).	0.143	0.563	0.197	0.027	-0.036	0.386
51. If I go to grocery stores independently, I can easily ask the seller for the information I need.	0.106	0.317	0.274	0.028	0.188	0.429
52. I can easily get involved in political discussion aiming at improving nutritional status of Iranian people.	0.213	0.304	0.388	0.072	0.182	0.765
53. I am interested in taking an active role in activities aiming at promoting healthy diet.	0.178	0.461	0.423	0.261	0.045	0.743
54. I expect my school or work place to serve healthy foods.	0.057	0.039	0.717	0.015	0.249	0.751
55. I try to convince others (e.g., my family or friends) to eat healthy foods.	0.066	0.376	0.601	0.057	0.113	0.738
56. It’s important for me various healthy foods to be available to choose in the school canteens.	0.024	0.038	0.780	0.092	0.162	0.737
63 I am an environmentalist and willing to voluntarily work toward supporting Eco-friendly methods of food production.	0.188	0.150	0.525	0.123	0.096	0.751
64. I am interested in voluntary activities to reduce unhealthy snacks and fast food availability in my neighborhood, school or workplace.	0.220	0.184	0.632	0.119	0.193	0.727
57. I am usually influenced by nutritional recommendation made by my family and friends.	0.024	0.187	0.312	0.448	0.125	0.488
58. I trust different diets that I read about in newspapers and magazines.	0.008	0.166	0.105	0.753	0.015	0.410
59. I believe that the scientific findings on nutrition, food and diet discussed in mass media are correct.	0.058	0.205	0.068	0.676	-0.117	0.444
60. It’s difficult for me to distinguish between scientific and non-scientific materials about diet.	0.143	0.068	0.018	0.434	0.098	0.495
61. The claims advertised by food manufacturers about the positive health effects of their food products are reliable.	0.077	0.030	0.041	0.617	0.020	0.468
62. I don’t easily accept food and nutrition information I receive from virtual networks, and research about their truthfulness.b	0.062	0.406	0.301	0.241	0.237	0.644
65. If you eat a package of cheese with the following label information, how much calories you will get from this product?	0.003	0.148	0.048	0.124	0.445	0.614
66. Considering food labels of product 1 and product 2, which one is more appropriate for a person on a low calorie diet?	0.109	0.028	0.042	0.143	0.516	0.319
67. Imagine you are in a grocery store and there are two kinds of yogurt which their food traffic lights labels are shown below; which product is a healthier choice?	0.079	0.054	0.015	0.094	0.580	0.316

KaiserMeyerOlkin (KMO) was 0.844. P value for Bartlett’s Test of Sphericity was <0.001 (χ²=3325.51, Degree of freedom=703). In primary model of skill domain, Cronbach’s Alpha for functional skills, interactive skills, advocacy, critical analysis of information and food label reading skills were 0.811, 0.468, 0.773, 0.543, and 0.550 respectively. ^aAfter removing item 30, α if item deleted for item 34=0.823. ^bThese items were deleted in the final model of skill domain