Weight loss and perseverance

I cant seem to get my wife to wrap this around her head. She exercises like mad daily. But then eats all the wrong crappy food all day and gets no results at all. Sometimes she makes a meal that her and the kids will eat, and I abstain because I tell her, I'm sorry, but i wont put that in my body. Then she says "I will try your keto, but am only cutting down to 140G of carbs intake daily". I shake my head, and tell her, you will not see any results at all with that. Can lead a horse to water, but you cant make em drink it.