Apparently it was a murder suicide?? wth
http://ktla.com/2017/10/20/o-c-man-who-was-reported-missing-after-hike-in-joshua-tree-killed-girlfriend-then-himself-detectives-believe/
Calories in vs. Calories out.
If you want to lose weight, eat under the calories using your TDEE (total daily energy expenditure). If you want to gain weight do the opposite.
Just remember, you'll never out-exercise your diet.