Uncoupling sweetness and energy in habitual high and low consumers of artificial sweetners: effects on appetite

In the natural world, sweetness as a taste is almost always found in association with energy. Associated with energy and the physiological effects of energy, sweetness can exert a number of effects on appetite. With the development of artificial sweeteners however, sweetness and energy can be uncoupled. Uncoupling sweetness and energy, the consumption of artificial sweeteners may have profound effects on appetite and appetite control. Uncoupling sweetness and energy in the single consumption of artificial sweeteners has previously been widely investigated and is demonstrated in this thesis in Study 1. Sweetness uncoupled from energy can stimulate appetite; an effect which can be explained with reference to the natural sweetness-energy relationship. Uncoupling sweetness and energy in the habitual consumption of artificial sweeteners, remains uninvestigated. Uncoupling sweetness and energy in habitual high consumers of artificial sweeteners: effects on appetite and appetite control were investigated in this thesis by comparing habitual high consumers of artificially-sweetened beverages with habitual low consumers. Habitual high and low consumers of artificially-sweetened beverages were defined in Study 2. Effects on appetite were investigated in Studies 3,4,5, and 6, using highly controlled nutritional challenges: Studies 3 and 4- responses to sweetness and energy consumed as a drink; Study 5- responses to sweetness consumed as a meal; Study 6 - responses to sweetness, sweetness intensity and dietary fat consumed as a drink. Effects on appetite and appetite control were investigated in Studies 7 and 8, using self-report questionnaires measuring general eating attitudes and behaviours - Study 7; and using specialized food diaries measuring specific eating behaviours - Study 8. Throughout this thesis, in female participants, the habitual consumption of artificially-sweetened beverages was found to be associated with high levels of overall appetite (Studies 3,4,7 and 8), differing responses to sweetness and energy (Studies 4 and 5), high appetites for sweetness and following sweetness (Studies 3,5 and 8), and a highly restrained and cognitively controlled eating style (Studies 7 and 8) (including a high consumption of fluids (Studies 3,4,5, and 8)). In male participants, the habitual consumption of artificially-sweetened beverages was associated with a highly restrained and cognitively controlled eating style (Studies 7 and 8). High appetites for and following sweetness were not specific to high consumers of artificially-sweetened beverages and are explained as a result of high preferences for sweetness. A high overall appetite, differing responses to sweetness and energy, and a highly restrained and cognitively controlled eating style can be explained as a result of the habitual uncoupling of sweetness and energy, with reference to the natural sweetnessenergy relationship, and may demonstrate persistence and extinction of that relationship. A high overall appetite and a highly restrained and cognitively controlled eating style however can also more appropriately be explained as a result of associations with the deliberate self-selection of a habitual high consumption of artificial sweeteners, and may be unrelated to the uncoupling of sweetness and energy. A high appetite and a highly cognitively controlled eating style may be a result of high levels of weight and high levels of weight concern in the habitual high consumers of artificial sweeteners. A high B. M. I. or weight concern in the habitual high consumers however, can not explain the differing responses to sweetness and energy. Differing responses to sweetness and energy can only be explained as a direct result of the habitual uncoupling of sweetness and energy, as a demonstration of an extinction of the natural sweetness-energy relationship. Effects in male participants and differences between males and females can be explained as a result of a lesser importance of taste in appetite in males or as a result of a lesser concern over weight. Uncoupling sweetness and energy in habitual high consumers of artificial sweeteners thus, is associated with various effects on appetite and appetite control. The majority of these effects are considered to result from associations with the deliberate self-selection of a high consumption of artificial sweeteners - high levels of weight and weight concern. Evidence was also found however, suggesting an association with an extinction of the natural sweetness-energy relationship and an adaptation to sweetness.