K’zayit at Meal

My doctor has ordered me to keep my carbohydrate intake to a minimum. I know that there is a machloket if a k’zayit of bread at the beginning of a meal exempts all food from a brachah, or if one must continue eating bread throughout. What is the helachah? Can I measure out 6 grams of bread before Shabbat, eat that at the beginning of the meal and keep eating other foods without a brachah, or should I recite the appropriate brachah on each food, based on the principle of “one who has removed his hands from the bread”? Thank you in advance.