hmmmm, I'd have to think about that. I guess it depends on a couple things. For instance, I can be disorganized and somewhat scattered but if I make a plan to get things organized it usually works for a while and then I get sidetracked and it all goes to hell again. So it helps to have someone that has an expectation that things will get done. I am totally different at home vs. at work in that regard. As far as the friend who eats too much (and my baddie for smoking) thats alot harder. I'm not sure facilitation or motivation can be achieved until the person is ready to change. It sounds kinda stupid as I look at it now but its really hard to explain why we keep doing what we do. I'm not sure there even is an explanation.
1) He has an eating disorder. What he is doing is called "emotional eating." If he only ate when he was truly hungry, healthy food would taste better to him, but since he eats on emotional impuse and isn't truly hungry, of course he is going to go for treats like ice cream and cake.
He needs to re-learn his "hunger" feeling properly so he knows the difference between being truly hungry and wanting to feed his addiction (sorry for the pun.) Hunger is an empty feeling. Hunger builds slowly. Hunger is satiated by any food, not just specific desired items.
Emotional eating comes on suddenly, seems overwhelming, and is usually a craving for something very specific.
2) Have him keep only healthy foods in his house so that if he does have the impulse for junk, he'd actually have to leave the house to get it.
3) All or nothing mentality can make dieters binge. If he feels too restricted by his new diet, he'll be that much more tempted to overeat the wrong things. If he sets aside, say, one day a week where he allows himself treats, he can make a gradual change in eating habits over time instead of feeling like he is on some horrible restricted diet where he can't have ice cream for months. It's kind of like the principle of the harder you try to not think about something, the more you'll think of it.
4) He may need counseling.
"Sentiment without action is the ruin of the soul." - Edward Abbey
To the OP: I've never been fat, but I have been in the same situation with someone near and dear to me. A dose of cold cruel reality is the first step... Take a candid photograph. One-on-one, make it clear you're not trying to be a bully; you really care and you're not resting easy. When a friend or family member is obese; sadly, they're not as fun to hang around. They typically don't have the stamina or a healthy state of mind.
Help set small realistic goals with some type of reward to build the momentum required to reach the finish line and sustain. Talking about it is not enough. I think going with your friend to the park for a jog or to the gym for some type of cardio workout at least 3-days a week would be just the thing to kick off the weightloss and the optimism. It's all in the power of the mind.
I can tell you that an INFP will like it very much to have a close friend to go and do stuff with them. Anybody with an addiction is going to initially feel overwhelmed by the bigger picture. So again, small acheivable goals w/ Ben & Jerry's rewards? Something like that just might be very effective.
Being active and working out on a regular basis is sooo important!
^ I don't understand that mentality. If not for you, then who? There are people in this world that are dying of cancer, missing limbs, you name it... people that would give anything to have the simple task of losing weight in order to be whole and healthy again.
Leave him alone, don't even mention it ever, and set a good example with your own eating habits and activities/exercise. Don't even offer to help with diet/exercise unless he specifically asks for it.
It sounds like he could use some professional help but again, pushing or even suggesting it will probably backfire. Just be supportive if he chooses to do it. It's his life. You guys are probably hurting the issue by bringing it up over and over and making him stubborn about it.
^ You're ISTP, no? I agree with your advice when dealing with ISTP, but dealing with INFP is not the same; it's not like walking on eggshells. If the INFP trusts you, the INFP will respect you, respect what you have to say good/bad, and will give your concerns proper consideration. INFP is not going to naturally dig their heels in or ever hate you for seriously caring (unless you're verbally abusive)! You want an INFP to move? You gotta speak up and push back a little! INFP might grumble about it, but they'll eventually see the light at the end of the tunnel (that you have their best interest in mind).
As for everyone else advising to leave the friend alone, we don't know all of the facts do we? If this friend is morbidly obese, then the OP's concerns for some type of intervention are warranted.