How to Know if You’re Losing Fat or Muscle?

You’re Hitting a Plateau With Your Workouts
Overtime, as you workout you should be able to get stronger and do more and more reps with less rest. If you find yourself hitting a plateau, it can be a sign that you are losing muscle with your diet.
You Feel Tired During the Day
If you’re working out you should have more energy during the day, not less. If you find yourself staying tired during the day instead of having more energy, it could be another sign that you’re losing muscle.
A Body Fat Scanner Shows Muscle Loss
Many gyms and some nutrition stores have body composition scanners that will tell you muscle and fat percentages. One way to know for sure is to track your body composition over time with a scanner so that you can spot muscle loss right away.