When you exercise (lift weights) your body uses energy to burn calories and in order to make up for the calories that are lost during your exercise you should be eating a protein and carbohydrate source post workouts. This will stabilize your blood sugar and provide needed energy.
After completing a weight lifting session your body starts to break down muscle protein and carbohydrate stores. This process can be confusing to some people but know that this is when our body’s muscle building takes place. You will notice after a workout you may feel fatigued. Eating after your workouts with the right sources should definitely help your energy levels along with helping to build the muscle you worked so hard for during that session!
Because of this process taking place it is best to eat post workout within a 45 minute window. I personally tend to eat anywhere from 15-45 minutes after a lifting session.
However, keep in mind that if you aren’t able to eat within this post workout window it is not the end of the world and you are not going to simply lose all the muscle you worked hard for! Nothing is immediate or absolute in those terms, so do not fret if you find yourself going longer without eating. The most important aspect of all is actually not meal timing but getting in all the needed macros for your daily allowance by the time your day ends. Daily intake > Meal timing. So do your best to meal time according to your goals but don’t stress if some days it feels impossible.