I have no idea how to support someone trying to lose weight, when they skip going to the gym and munch on snacks late at night. If I support the snacking, I am not suporting the fitness goal, if I support the fitness goal I don't support her feelings and moods. I've tried having her workout with me, but she has zero interest in doing anything that requires breaking a sweat.
The hardest part about getting into a new routine such as working out is that after a while you lose interest and it starts becoming a chore. However, once you get over that you generally get used to it and don't really mind doing it or even start enjoying it. So the entire focus when starting a new routine should be on getting over that hurdle.
The best way to do this with regards to working out would be to find a way of enforcing working out daily. For example, I've made my schedule out so that I have about an hour or two between busy periods where I have absolutely nothing to do; this has
really helped motivate me to get to the gym, because what else am I going to do? I'm at the point now, though, where I've passed the hurdle and just go because I generally look forward to it.
But that's just one example. Another could be preparing your workout clothes the day before, making a workout playlist that you're hyped on listening to, rewarding yourself for working out (after I work out I'm going to _____), etc...
I can't actually really think of anything that would be super effective besides tailoring your (her) schedule like I have, but it's a
lot easier to use these kind of things to switch over to eating healthy.
First, I make my lunch for the next day the night before. That way, I'm not inclined to skip bringing lunch to work because I don't feel like making it in the morning, which means that I'd spend money on lunch and also probably buy something not that healthy.
Second, stop buying regular soda. Switch to diet. Diet soda in general sucks, but I've found that the main two sodas I drink (Coca-Cola and Sierra Mist) both have really good tasting diet choices: Coke Zero and Diet Sierra Mist. If you are a Pepsi person, my roommate has told me that Pepsi Max is good as well, and Diet Dr. Pepper is pretty damn good, too. Regular diet (Diet Pepsi, Diet Coke, etc...) sucks but don't let that influence your perception about all diet sodas.
Also with this is to
stop drinking juice. Yes, juice can be good for you, but only in pretty small amounts; otherwise you're just consuming a lot of unnecessary carbs. The only juice that I drink is a glass with breakfast once in a while and a glass of pomegranate-cranberry juice a few times a week.
Third, on snacks. Find healthy snacks
that you like and stick with them. The important thing is that you like them; snacks are meant to be enjoyed. However, don't go crazy with it; Sun Chips are healthy and delicious, but eating an entire bag of them isn't good for you. Also, in the evenings stay away from carbs; when you sleep your metabolism slows down and more of those carbs will be stored as fat. Stick to vegetables ideally (those Green Giant microwavable vegetable things in sauce are awesome night snacks), but something like fat free yogurt is good as well.
Fourth, when you go shopping shop healthy. Shopping is the most important part of eating healthy, because you are determining what food you will have available to you for the next week or two. If you can resist the urge to buy those potato chips or cookies you won't have the temptation to eat it because you won't have access to it.
Finally, going out
sucks when you are trying to control what you eat. Getting salads at nice restaurants blows, because you want to get the steak, or the rib, or the burger. If you can control yourself then just get a salad; they're usually pretty good, even if it's not as satisfying as a rack of ribs. If you aren't able to control yourself (like me) then don't go out to eat as much; staying in and cooking is just as enjoyable (to me, at least) and you can control what you're eating, so you can make something that's both healthy
and delicious.
Oh, and I know it sucks, and is probably the worst thing that I've ever had to do in my life, but cut the beer. If you have to have alcohol (not in the alcoholic way, but in the 'I want to get buzzed and chill out for a bit' way) then have a rum/whiskey and diet (use the Coke Zero). I used to drink a beer probably every night or every few nights, and I've gotten it cut down to maybe 1 or 2 a week. It reaaaally sucks but there's a plus side - now instead of buying a 24/30 pack I can buy a higher quality 6-pack and enjoy it much more. Also, if I go out to bars I'll pregame ahead of time with Jack & Coke Zero and when I get there I'll order rum & diet's and maybe light beers. Although I do admit when I get drunk I kind of stop caring about it.