to influence, adiposity directly or indirectly, and might explain the positive association between viewing and adiposity. Only the last is the committee’s focus.

  • Television viewing might take up time that otherwise would be given to greater physical activity, and more physical activity could lead to higher calorie expenditure, which could lead to lesser adiposity.

  • Television viewing might be an indicator of a preference for a more sedentary lifestyle, and more sedentary activity could lead to lower energy expenditure, which could lead to greater adiposity.

  • Television viewing might be a context for snacking, and more snacking could lead to higher calorie intake, which could lead to greater adiposity.

  • Television viewing might blunt one’s sensitivity to satiety cues, and greater insensitivity to satiety cues could lead to greater calorie intake when eating during viewing, which could lead to greater adiposity.

  • Television viewing might reduce one’s metabolic level, and a lower metabolic level could lead to less efficient processing of calorie intake, which could lead to greater adiposity.

  • Television viewing might be an indicator of exposure to depictions of eating and drinking within the program (either scripted or product placement), and more exposure to these depictions could increase preferences, purchase requests, and other precursors of diet which then increase calorie intake and could lead to greater adiposity.

  • Television viewing might be an indicator of exposure to food and beverage advertising, and more exposure to this advertising could increase preferences, purchase requests, and other precursors of diet, which then increase dietary intake and could lead to greater adiposity.

Realistically, several of these variables and pathways may operate simultaneously to influence adiposity. The question for the committee is whether exposure to television advertising is among them, not whether exposure to television advertising is the sole influence or the most important influence. None of the 17 results that tested enough variables to receive a medium causal inference validity rating covered all seven plausible explanations using measures other than television viewing. Not one included direct measures of satiety cues, metabolic rate, consumption depictions, or television advertising. For each of the other plausible explanations, at least one study tested one or more of them using measures other than television viewing.

In addition to examining what happens to television advertising as a potential causal variable when measures of television-related nonadvertising variables are included in the analysis, the possibility that the appar-



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