Table 1.

Measurement of weight- and shape-related behaviors.

Construct	EAT 2018 participant behaviors	Perceived friend behaviors	Friends’ actual behaviors
Frequent dieting	How often have you gone on a diet during the last year? By “diet” we mean changing the way you eat so you can lose weight.	For each nominated friend: Does this friend do any of the following to lose weight or keep from gaining weight … Go on a diet? b. Take diet pills, vomit, use laxatives, or use diuretics	How often have you gone on a diet during the last year? By “diet” we mean changing the way you eat so you can lose weight.
	5 response options: “never” to “I am always dieting”; 5+ times contrasted with fewer (test-retest r = 0.66)	Response options: yes, no, I don’t know	5 response options: “never” to “I am always dieting”; 5+ times contrasted with fewer (test-retest r = 0.66)
Extreme weight-control behaviors	4 items: Have you done any of the following things in order to lose weight or keep from gaining weight during the past year? Used diet pills, made myself vomit (throw up), used laxatives, used diuretics (water pills).	For each nominated friend: Does this friend do any of the following to lose weight or keep from gaining weight … Take diet pills, vomit, use laxatives, or use diuretics?	4 items: Have you done any of the following things in order to lose weight or keep from gaining weight during the past year? Used diet pills, made myself vomit (throw up), used laxatives, used diuretics (water pills).
	Response: yes/no for each behavior; use of any contrasted with none (test-retest agreement = 93%)	Response options: yes, no, I don’t know	Response: yes/no for each behavior; use of any contrasted with none (test-retest agreement = 93%)
Use protein powder, shakes, or a pre-workout drink	2 items: Have you done any of the following things in order to increase your muscle size or tone during the past year? Used protein powder or shakes, used a pre-workout drink acids, hydroxyl methylbutyrate [HMB], DHEA, or growth hormone)	For each nominated friend: How often does this friend do the following things to increase muscle size or tone … use protein powder, shakes, or a preworkout drink (such as Jack3D, Cellucor C4 or JYM)?	2 items: Have you done any of the following things in order to increase your muscle size or tone during the past year? Used protein powder or shakes, used a pre-workout drink acids, hydroxyl methylbutyrate [HMB], DHEA, or growth hormone)
	Response: yes/no for each behavior; use of either contrasted with none (test-retest agreement = 88%)	Response options: Never, Rarely, Sometimes, Often, I don’t know	Response: yes/no for each behavior; use of either contrasted with none (test-retest agreement = 88%)
Use steroids or another muscle building substance	2 items: Have you done any of the following things in order to increase your muscle size or tone during the past year? Used steroids, used another muscle-building substance (such as creatine, amino acids, hydroxyl methylbutyrate [HMB], DHEA, or growth hormone)	For each nominated friend: How often does this friend do the following things to increase muscle size or tone … use steroids or another muscle-building substance (such as creatine or growth hormone)	2 items: Have you done any of the following things in order to increase your muscle size or tone during the past year? Used steroids, used another muscle-building substance (such as creatine, amino acids, hydroxyl methylbutyrate [HMB], DHEA, or growth hormone)
	Response: yes/no for each behavior; use of either contrasted with none (test-retest agreement = %)	Response options: Never, Rarely, Sometimes, Often, I don’t know	Response: yes/no for each behavior; use of either contrasted with none (test-retest agreement = %)