Hi, if you are speaking about legal theories, I think that the general theory of good faith is a good starting point to protect consumer, forcing for example the professional to inform the consumer during negotiations in order to the consumer to make a better choice. Please see my article: "la protection du consommateur dans la partie générale du droit des obligations"
In addition to that, regulations protecting consumers (e.g. allowing him to exit the contract within a certain time frame) may also help.
In advertising context, perhaps “Persuasion Knowledge Model” can be relevant. Consumers tend to rely on their “Persuasion knowledge“ when they assess advertising such as influencers marketing to protect themselves from any deceptive content.