Aaron Marino of alpha m. discusses pre and post workout meals, which depend on what you’re doing at the gym that day.
If weight training is on the agenda, something small and substantial meal is advised. The meal should be slow release carb like sweet potato, oatmeal, or Fiber One cereal. The meal gives the fuel needed to be strong without being bloated.
If a cardio session is planned, an empty stomach is recommended. An empty stomach is not going to burn muscle. Muscle doesn’t add that fat, and reciprocally, doesn’t go away that fast. This is a very common misconception.
After a workout, eat something that is easily absorbable like a liquid protein powder or shake. Also eat a piece of fruit or something higher in sugar carb is also appropriate right after a workout.