Apple Watch, confused with MFP integration

quackers82

Can somebody explain the way MFP works with the Apple Watch as i'm completely confused. The only form of exercise i do is walking.

I've hardly done any today, but still 6200 steps, but its only added 45 calories to MFP. The Activity App on the iPhone says i have done 340 active calories, 2147 total.

If i tell the watch i'm doing a walk it writes much larger calories to MFP, but i think its way off, it will give me 300 calories for a 30 min walk at 4mph, i would expect more like 150 for a 6ft 3 male at 185lbs. Are the walking activity calories quite accurate with it talking my pulse at the same time, so i am infact using up close to 300 on those 30 minute walks?