I suffered from this until I cut out simple carbs at lunch. Bread, pasta, potatoes, and rice all send me to sleep if I have them. Salads and meat I can pig out on without problems.
I started intermittent fasting, eating all my calories at home at night, and the result is no blood sugar dip or post-lunch fatigue at work.
When you add up the meal prep and time eating every week (for what are generally low quality calories), it's a tremendous time saver, in addition to the productivity boost.
