Have her use MyFitnessPal to track her foods and have her record EVERYTHING that she eats and drink. You, as her friend (on the app) can go in and look at her food log and give her feedback on her eating (regularly). If she’s overweight/obese she just needs to lose weight and naturally the body will lose fat/weight where it stores it. However, you can not pin point where you want to lose weight. I think it’d be important for you to educate her on the myth that she can lose weight on just her arms. We’ve been taught that you can’t spot reduce, so educate her on it. Encourage her and guide her to eating healthier then the weight will come off.
I require all my clients who want to lose weight to keep a food journal. I use to look over their journal regularly and give them feedback. Now, my company has a little bit over 100 clients, so it’s too much for me to do it all.
Now, I pay one of my trainers over $350 per month to check food logs and assist clients on making better food choices. It has done wonders for my company. I recommend, all trainers use MyFitnessPal in some form for their clients. For the most part it’s just clients being aware of how much crap they’re eating. Naturally, they do better when they can see the junk that they record.