Like others have said, I've tracked calories and macros with My Fitness Pal on and off over the years. My nutrition habits , along with my husband and kids', have improved dramatically with time.
I use My Fitness Pal to keep track of my weight and heart rate. It is certainly interesting to be able to graph my weight over the last few years and gain incentive to not exceed my maximum weight.
Similar to another comment, my CGM integration with my smartwatch has completely changed my life. I can see an accurate BG rating at anytime. Every type 1 diabetic should have one.
Ended up getting a seriously bad case of UC that resulted in multiple changes in my life. Between my drug management, new dietary constraints, communicating with my doctor (via portal - you know you can never reach anyone anymore by phone), and an app to manage my surgery recoveries and tracking, I don't think I'd be functioning today without the combination of things my phone gave me. This is especially true since my illness and recovery left me bedridden for a decent amount of time.
Tracking weight and calories on MyFitnessPal keeps me honest. Also, after having A-fib and the subsequent cardioversion, it is comforting to check my rythm on my own with Kardia. Not sure I'd categorize any of this as "life-changing" - I'd call it convenience.
The 7 minute workout app featured in the New York Times was "prescribed" by my doctor (he told me I should do it twice a week). Before that, I rarely had an hour free in my schedule to hit the gym. Now my phone gives me a quick guided workout that I can squeeze in before breakfast with close to the same health benefits of a gym membership.
Been using the Fitbit app, the My Fitness Pal and the Map My Walk app for several years. Since doing so my weight has come done and my overall fitness has improved. I like to compete against what I've accomplished and I believe my long term health will only get better.
Been using it for Strava to track exercise.
I've been using MyFitnessPal for over 8 years - and by counting calories, I've been able to keep off most the weight I lost. MyFitnessPal helped me understand how much many calories really were in my daily diet.
Yes. I set some new fitness goals for myself a few months ago and use my apple watch and apple health to track my progress daily.
Use a 7-minute High Intensity Interval Training (HIIT) app that has helped me get back in shape after injury. Just the calendar feature drives regular usage.
After an MI, I was able to continuously monitor my pulse during cardiac rehab with my phone attached HR monitor staying in training mode while not overtaxing my heart. Additionally, I purchased an FDA approved EKG device from Kardia Mobile for $100. It let me take and share EKG strips. Upon seeing the lack of PVC’s in the EKG’s, the cardiologist let me exercise more strenuously and shed the external defibrillator vest I was wearing 24/7. So yes, it put the power of information in my hands during my recovery.
Using the free version of My Fitness Pal helped me visualize correct portions and gave me freedom to make healthy choices with the foods I like to eat . That usage supported life style changes that have stuck. I don’t use it religiously anymore but check in now and then to make sure I don’t drift back to old habits
A few years ago I had a doctor's appointment go poorly, with weight and cholesterol. He recommended diet and exercise before starting statins. I'd heard of this pokemon go game on mobile and started taking walks with it. Those walks turned into runs, combined with a couch-to-5k app. Two years later I was 45lbs down and training for a marathon.
Continuous glucose monitor (Dexcom) readings visible on my phone, including visual trends, alarms, etc. As a type 1 diabetic, has led to significant improvement in my A1c.