Final answer:
The most suitable type of food for a client following a low glycemic index diet would be options that are high in whole grains.
Step-by-step explanation:
A low glycemic index diet prioritizes foods that have a low impact on blood sugar levels. Therefore, the most suitable type of food for a client following this diet would be options that are high in whole grains. Whole grains, such as quinoa, brown rice, and oats, have a lower glycemic index compared to refined carbohydrates and are digested more slowly, resulting in a steadier rise in blood sugar levels. These foods provide sustained energy and are generally healthier options for managing blood sugar levels.