Hi Kevin,

The 'ella' in this part of the passage is referring to 'la comida'- the food, the meal in this instance.

Por todo esto, piénsatelo dos veces cuando suene el despertador, y procura no saltarte esta comida, puesto que consumiendo alimentos sanos en ella podrás desempeñar tus tareas con gran entusiasmo.

 

 

My understanding of this section above is more or less...

So, think twice when the alarm clock rings/sounds, and try not to/ make sure not to skip this meal (la comida) as eating healthy foods (nutrients) from it will enable you/ you will be able to perform your tasks with great enthusiasm.

Hope this helps a little. :)