Good intentions, bad habits, and effects of forming implementation intentions on healthy eating

A field experiment demonstrated that forming implementation intentions was effective in changing complex everyday behavior, in this case establishing a healthier diet. Implementation intentions concerned a specific plan for when and how to act. The effect of implementation intentions was additive to the prediction of healthy eating by behavioral intentions to eat healthily. Implementation intentions were pitted against individual differences in counterintentional (unhealthy) habits. The effects of implementation intentions and counterintentional habits were independent, suggesting that implementation intentions did not break the negative influence of unhealthy habits, and yet managed to make those with unhealthy habits eat healthier in habit-unrelated respects.