I eat low carb, no wheat no grains. I eat moderate fats and protein as well as a lot of greens.
I sometimes find my energy for late afternoon workouts is waning. Because of my job I workout at 3:30 or 4 pm.
I recently added some beans to my diet in the mid-day. Just a cup or so of homemade black beans usually.
This seems to have solved my problem with lack of energy and my workouts have gotten better and stronger.
Legumes are used by the body differently than many carb rich food. The fiber has a lot to do with that too.
Basically the enrgy boost is a storng one and the glucose rise is low or minimal. This should be your main concern.
You don't want your blood sugar rising much over the low 100's. So beans seem like a good answer for me. Hope they help you too.
Recipe for Black Beans:
I cook black beans in olive oil with garlic, onion and peppers. Saute a cut up onion, some fresh garlic and sweet or hot peppers in about two tbsp of oil, then add the black beans with the liquid (if canned). A 1/2 cup of white wine is good to add too. Turn the heat down and let it simmer awhile. Then enjoy.