Dietary monotony and food cravings in young and elderly adults

Many hypothesized mechanisms for food cravings focus on nutritional deprivation. However, outside of the laboratory, nutritional inadequacy is often confounded with dietary monotony. Therefore, one aim was to examine the effects of a nutritionally adequate, liquid, sweet, monotonous diet on food cravings in young and elderly adults. In addition, previous retrospective questionnaire work has indicated that elderly individuals report fewer food cravings than do young adults. Because there are possible age differences in cognitive capacity, another goal of this work was to develop a prospective method (i.e.. a method that depends less on memory) of studying cravings that permits comparison of adults of different ages. Young adults reported significantly more cravings per day during the monotony manipulation than during the baseline period. Therefore, nutritional deprivation is not a necessary condition for food cravings. There were no gender differences. The increase was due primarily to a greater number of cravings for entrees (i.e., foods that differed in sensory quality from the monotonous diet). Cravings for sweets did not change. In contrast to predictions that liking for the monotonous diet would decline as a result of "repetition revulsion," there was no significant change in liking for the diet over the study period. In contrast to the young adults, elderly subjects were not responsive to the monotony manipulation. Elderly men reported almost no cravings at any time during the study. Elderly women reported as many cravings as did young adults during the baseline period, but did not show an increase in cravings during the monotony period. This lack of response to dietary monotony by the elderly could result in nutritionally inadequate diets.