Doug Lisle, psychologist at True North Health and coauthor of The Pleasure Trap, argues persuasively in his talk “How to Get Along Without Going Along” (excerpted here on YouTube) that the biggest reason people are hostile when we start eating better is that they perceive a threat to their status.
As I was discussing this theory, stream-of-consciousness fashion, on my online TV show yesterday, I stumbled upon the conclusion that this is correct, and incomplete.
Status is important to us, but it's not the only thing. David McLellan's Three Needs Theory posits two additional drives: affiliation (love, friendship, closeness, affection), and achievement (accomplishing meaningful goals).
When we improve our diets, our partners can legitimately worry about suffering in those domains as well.
They may worry about us not being able to go out to the same places and enjoy the same social scenes anymore.
They may realize that eating differently requires shopping, prepping, and cooking differently, and that they lack competence in the new ways of doing things.
According to McLelland, each of us has a motivation profile, made up of different valences of the three main drives. So if you focus on assuaging your partner's status shortfall when they are actually driven more by affiliation, you could be missing the most important part of the equation.
Lisle's advice – humble yourself and do what you can to restore their perceived status – holds for affiliation and achievement as well. Reassure them that the relationship will only grow stronger, and that their strengths and skills will be important to you as you transition to a healthier way of eating.
Once the perceived threat is neutralized, the rest is just details.